Apportionment of Damages Between Multiple Tortfeasors
The Honourable Mr. Justice Goepel and Seva Batkin, Law Clerk
Untangling the different sources of damage and loss may be
nigh impossible. Yet the law requires that it be done …
…
It is important to distinguish between causation as the source of
the loss and the rules of damage assessment in tort.1
I.
Introduction
¶1
Imagine a plaintiff whose bad luck had him injured in three separate incidents over a
span of several years. While he is entirely blameless for the first and third incidents, he is
found to have been partially responsible for the second one. He claims a hotchpotch of
physical and psychological injuries under all possible heads of damages. To further
complicate matters, at least some of the claimed and clinically proven injuries are similar to
the conditions he had prior to the first incident. For example, while an expert testified that
severe depression caused by the physical injuries suffered in the incidents has made the
plaintiff unemployable, the defendant produced medical records that indicate that the plaintiff
suffered from depression before the accidents and has even been hospitalized for a suicide
attempt. To complicate matters further, only two of the three defendants are party to the
action, the third being an unknown assailant. Given this myriad of factors, and given the
findings of full and partial liability, how should the damages be apportioned between the
tortfeasors?
¶2
Unfortunately, the law on this subject is far from clear, providing confusing and at best
partial or at worst conflicting answers. Most notably, there appear to be two leading decisions
on apportionment of damages between tortfeasors. In the classic case of Long v. Thiessen,2
the British Columbia Court of Appeal established the well-known formula for apportioning
1
2
McLachlin C.J.C. in Blackwater v. Plint, 2005 SCC 58 ¶74 and 78 [Blackwater].
Long v. Thiessen (1968), 65 W.W.R. 577 [Thiessen].
damages between tortfeasors independently liable for separate tortious incidents, placing the
burden on the second tortfeasor to prove the damages caused by the first tortfeasor to
reduce his own damages accordingly. However, in Athey v. Leonati3 and subsequently in G.
(E.D.) v. Hammer,4 the Supreme Court of Canada held that tortfeasors liable for separate
tortious incidents, which cause a single injury, are jointly and severally liable to the plaintiff for
all of the damages, and apportionment is merely an application of the provincial Negligence
Acts. Not only do these rules present an apparently intrinsic conflict, but they also fail to
address many aspects of the above hypothetical scenario, such as the plaintiff’s contributory
liability for one of the accidents or the pre-existing conditions. Of course, each of these issues
has been at one time or another individually addressed by the courts. However, the methods
developed to resolve these issues do not always congruently integrate Thiessen, Athey or
each other.
¶3
For the most part, the conflict between the two approaches has remained tacit and there
have been no appellate decisions comprehensively reconciling the two. As a result, recent
trial decisions range from the blunt conclusion that Thiessen was and remains the law of
British Columbia,5 to a considered illation that between the "two conflicting approaches to
assessing damages”, “the Athey v. Leonati approach should prevail.”6
¶4
Fortunately, neither the status quo nor a mortal contest between the apparently
conflicting approaches is necessary. The confusion is not or at least should not be what
approach currently reigns supreme, but rather what combination of rules and principles are
applicable to a particular situation. Thus, development of a comprehensive taxonomy of
situations and identification of the applicable principles is the key to reconciliation. Based on
existing authorities, this paper proposes a hierarchical taxonomy of situations, comprising
eight categories describing different types of tortious causes. Furthermore, this paper strives
to outline a step-by-step approach for apportioning damages under the principles applicable
to each of the categories. Keeping with the adage that a picture is worth a thousand words,
the proposed taxonomy is illustrated in following figure:
3
Athey v. Leonati, [1996] 3 S.C.R. 458 [Athey].
G. (E.D.) v. Hammer, 2003 SCC 52 [Hammer].
5
Kailey v. Kellner, 2007 BCSC 1449.
6
Ashcroft v. Dhaliwal, 2007 BCSC 533 ¶25 and 32 [Ashcroft].
4
2
Indivisible
Injuries
No Contributory
Negligence
Concurrent
Tortfeasors
¶5
Contributory
Negligence
Consecutive
Tortfeasors
Sufficient
Causes
Divisible
Injuries
Insufficient
Causes
Concurrent
Causes
Identify head
of damages
Consecutive
Causes
Sufficient
Causes
Discrete
Effects
Superimposed
Effects
Insufficient
Causes
A note to bear in mind is that this paper is written with a focus on a trial judge sitting
alone. Thus, the issues discussed in this paper are not distinguished as questions of fact,
which would be appropriately relegated to a jury, and questions of law, on which a judge
would instruct a jury.
II.
Identifying and Categorizing Injuries
¶6
Once liability is found, the first step is to assess what injuries the plaintiff has actually
suffered. The importance of this step should not be understated as it will guide the
subsequent analysis and ultimately dictate the appropriate method for apportionment of
damages.
¶7
In identifying the plaintiff’s injuries, the trial judge should be careful to consider both the
physical injuries directly caused by the tortious act or acts, for example back problems,
fibromyalgia, or cognitive problems associated with a head trauma, and the psychological
injuries that are caused by the physical injuries, for example depression. A trial judge should
bear in mind the distinction between the term “injury” as it is used in ordinary parlance –
generally referring to a physical harm suffered by a person, for example a broken leg, and the
meaning of this term in a legal sense – broadly referring to both the specific physical harm
and the consequential effects of such harm.
¶8
Once the trial judge identifies all of the injuries suffered by the plaintiff, the second step
is to determine whether each injury is divisible or indivisible.
¶9
The concept of divisible and indivisible injuries was elucidated by Mr. Justice Major in
Athey, corresponding to the basic principle of tort law that a defendant is only liable for the
3
injuries that he or she has actually caused.7 He explained that where both defendants are
found to have contributed to an injury, it is indivisible. Thus, in Athey, Mr. Justice Major found
that the defendants caused “a single indivisible injury, the disc herniation, so division is
neither possible nor appropriate.”8 As summarized by Mr. Justice Shaw in Ashcroft, “all
injuries caused or materially contributed to by a tort are said to be indivisible”.9
¶10 While the injury itself is said to be indivisible, that may be the only connection that is
found to exist between the tortious acts that caused or materially contributed to it. Thus, in
Horvath v. Thring, Madame Justice Ballance found an indivisible injury that was caused by
two separate torts:
In this case, the Crown's negligence is founded on conduct independent of the conduct
forming the basis of the Applicant's negligence. Entirely different allegations of
negligence were made against Thring than those alleged against the R.C.M.P. officers
and, vicariously, the Crown. More importantly, the trial judge found that the Crown on
the one hand and the Applicants on the other were responsible for separate torts
although those torts did combine to create the same damage. I find that the same
evidence would not have supported Constable Horvath's action against both the Crown
Thring, and General Motors. I find also that the defendants in this case did not act in
concert with each other in the commission of their respective torts. I conclude therefore
that the Crown and the Applicants were not joint tortfeasors.10
¶11 Divisible injuries are those which can be independently traced to a specific tortious
cause, and to which other tortious causes have not contributed. The simplest case of divisible
injuries was described by Mr. Justice Major in Athey: “one [tortfeasor] injuring the plaintiff's
foot and the other the plaintiff's arm”.11
¶12 Distinguishing divisible injuries is not always that simple. In Blackwater, McLachlin
C.J.C. held that in the absence of evidence that prior causes contributed to the injuries
suffered by the plaintiff from the defendant’s tortious acts, the trial judge had no choice but to
“isolate those traumas”:
The trial judge correctly apprehended the applicable legal principles. He recognized the
"daunting task" of untangling multiple interlocking factors and confining damages to only
those arising from the actionable torts, the sexual assaults (2001 decision, para. 365).
He tried his best to award fair damages, taking all this into account. He recognized the
thin skull principle, but in the absence of evidence that Mr. Barney's family difficulties
7
Athey, supra note 3, ¶24.
Ibid ¶25.
9
Ashcroft, supra note 6 ¶29.
10
Horvath v. Thring, 2003 BCSC 1656, aff’d 2005 BCCA 127 [Horvath].
11
Athey, supra note 3 ¶24.
8
4
prior to coming to AIRS had exacerbated the damage he suffered from the sexual
assaults he sustained at AIRS, the trial judge had no choice but to attempt to isolate
those traumas. Similarly, there was no legal basis upon which he could allow damages
suffered as a result of statute-barred wrongs committed at AIRS, like the beatings, to
increase the award of damages.12
¶13 Similarly, in McNaughton v. Ward, the Nova Scotia Court of Appeal affirmed the trial
judge’s conclusion that an earlier accident had nothing to do with the plaintiff’s current
conditions caused by a later workplace injury:
This was a case where the injuries were, and could be seen to be distinct and
separate.13
¶14 A single case may combine both divisible and indivisible injuries, with different
apportionment rules applicable to each. Thus, in Hutchings v. Dow, while Mr. Justice Cullen
found that “[t]he combined effect of the Accident and the Assault” caused the plaintiff’s
depression, an indivisible injury, he also found that the plaintiff’s back problems and seizures
were attributable the accident and the assault, respectively.14
¶15 Moreover, as will be described in more detail below, indivisible injuries can arise from
either tortious cause or from a combination of causes.
III. Indivisible Injuries
A. No Contributory Negligence
¶16 If the trial judge determines a specific injury to be indivisible, then the third step is to
ascertain whether the plaintiff has been contributorily negligent. At this stage, contributory
negligence is a “yes or no” threshold question, the answer to which will cardinally impact how
the plaintiff will be compensated. It is unnecessary, and sometimes impossible to determine
the actual extent of the plaintiff’s contributory negligence at this point. Thus, in a classic
situation of separate motor vehicle accidents, the trial judge needs only to determine whether
the plaintiff was contributorily negligent, to any degree, in at least one accident.
¶17 The reason why the answer to this question will so fundamentally affect the rest of the
apportionment exercise lies in ss. 1, 2, and 4 of the British Columbia Negligence Act:15
12
Blackwater, supra note 1 ¶82.
McNaughton v. Ward, 2007 NSCA 81 ¶99, aff’g 2006 NSSC 162.
14
Hutchings v. Dow, 2006 BCSC 629 ¶372 and 377-78, aff’d 2007 BCCA 148 [Hutchings].
15
Negligence Act, R.S.B.C. 1996, c. 333.
13
5
1 (1) If by the fault of 2 or more persons damage or loss is caused to one or more of
them, the liability to make good the damage or loss is in proportion to the degree to
which each person was at fault.
…
2 The awarding of damage or loss in every action to which section 1 applies is
governed by the following rules:
…
(c) as between each person who has sustained damage or loss and each other
person who is liable to make good the damage or loss, the person sustaining the
damage or loss is entitled to recover from that other person the percentage of the
damage or loss sustained that corresponds to the degree of fault of that other
person;
4 (1) If damage or loss has been caused by the fault of 2 or more persons, the court
must determine the degree to which each person was at fault.
(2) Except as provided in section 5 if 2 or more persons are found at fault
(a) they are jointly and severally liable to the person suffering the damage or loss,
…
¶18 Pursuant to s. 4, tortfeasors are jointly and severally liable for an injury that they caused
together, i.e., an indivisible injury. However, pursuant to ss. 1 and 2, where a plaintiff is found
to have been contributorily negligent, he or she is only entitled to recover from each tortfeasor
in accordance with the degree of that tortfeasor’s fault making the tortfeasors severally
liable.16
¶19 Where the plaintiff is found to have been wholly innocent in all of the tortious events that
caused or contributed to the indivisible injury, then the short answer is that he or she can look
to any of the tortfeasors for 100% of the damages. This is particularly important where only
some of the tortfeasors are party to the action17 or where recovery from one or more
tortfeasors is statute-barred:
… the fact that a person at fault may not be able to obtain contribution or indemnity
pursuant to s. 4(2)(b) did not absolve him or her from liability for the full amount of
damages under s. 4(2)(a).18
16
See Leischner v. West Kootenay Power & Light Co. (1986), 70 B.C.L.R. 145 (C.A.) and Laing Property Corp.
v. All Seasons Display Inc., 2000 BCCA 467 ¶76 [Laing]. Note that the Ontario Negligence Act is based on a
different principle, such that the plaintiff’s contributory negligence reduces the total compensable amount of his
injuries, but the tortfeasors are still jointly and severally liable for the rest: see Ingles v. Tutkaluk Construction
Ltd., 2000 SCC 12 ¶58-59 [Ingles].
17
See Ashcroft, supra note 6, where Shaw J. found that the plaintiff’s depression resulted from the accident
caused by the defendant and an assault caused by a third party.
18
Horvath, supra note 10 ¶23.
6
¶20 From the plaintiff’s perspective, his or her participation in the case effectively ends at
this point, having established all that is needed for compensation: liability and damages.
However, providing that more than one tortfeasor is party to the action, the trial judge will
then likely have to apportion damages between the tortfeasors under s. 4(2)(b) of the
Negligence Act.
¶21 The method to be used to apportion damages depends whether the tortfeasors are
concurrent or consecutive tortfeasors. Thus, the fourth step is to determine whether the
tortfeasors were concurrent or consecutive.
¶22 The term “concurrent tortfeasors” is borrowed from a classic torts text by Glanville
Williams:
Concurrent tortfeasors are tortfeasors whose torts concur (run together) to produce the
same damage. They are either joint concurrent tortfeasors (briefly, joint tortfeasors),
where there is not only a concurrence in the chain of causation leading to the single
damages but also (apart from nonfeasance in breach of a joint duty) mental
concurrence in some enterprise, or several concurrent tortfeasors, where the
concurrence is exclusively in the realm of causation.19
¶23 There are many examples of cases involving concurrent tortfeasors. In Horvath, the
driver and owner of the truck with which the plaintiff collided, and the Crown vicariously
responsible for negligent RCMP officers, were found to be concurrent tortfeasors because it
was the combination of their torts that caused the plaintiff’s injuries.20 In Aberdeen v. Langley
(Township), concurrent tortfeasors were the negligent driver who hit the plaintiff and the
municipality which installed a guard rail that created a hazard for the plaintiff.21
¶24 The single factor that identifies concurrent tortfeasors is that their torts “run together”22
to result in the injury to the plaintiff. While the actual negligent acts may be entirely different,
they culminate at a single point in time to produce the injury. For example, negligently
speeding driver and manufacturer who negligently designed or produced the breaks in the
driver’s car are concurrent tortfeasors because their torts combined at a single point in time to
injure the plaintiff.
19
Glanville Williams, Joint Torts and Contributory Negligence (London: Stevens & Sons Limited, 1951) at 1;
cited by Southin J.A. in Tucker (Public Trustee of) v. Asleson (1993), 78 B.C.L.R. (2d) 173 ¶158 (C.A.).
20
Horvath, supra note 10.
21
Aberdeen v. Langley (Township), 2007 BCSC 993 [Aberdeen].
22
Williams, supra note 19.
7
¶25 In the case of consecutive tortfeasors, the torts are not connected through a single
event and are completely independent of each other.
Typically, the injuries caused by
consecutive tortfeasors superimpose on the residual effects of the injuries caused by the by
the earlier tortfeasor(s). Consecutive tortfeasors have been found in a variety of situations.
Most commonly, for example in Thiessen,23 Hicks v. Cooper,24 and Zylstra v. Hughes,25
consecutive tortfeasors caused separate motor vehicle accidents. However, consecutive
tortfeasors are also sometimes responsible for completely different torts. In Hutchings, the
consecutive tortfeasors were the driver who caused the initial accident and the person who
later assaulted the plaintiff. The liability of such consecutive tortfeasors is also joint and
several because they have ultimately caused the same indivisible injury.
¶26 Once the trial judge determines whether the tortfeasors are concurrent or consecutive,
the fifth step is to employ the appropriate method to apportion the liability and therefore
damages between them.
1. Concurrent Tortfeasors
¶27 In the case of concurrent tortfeasors, the duty of the trial judge is “to determine the
degree to which each person is at fault”.26 Based on this apportionment of fault, the
tortfeasors look to each other to “to contribute to and indemnify each other in the degree to
which they are respectively found to have been at fault.”27 Naturally, this apportionment is
only possible between the tortfeasors that are before the court and to the extent that such
contribution is not barred by other statutes. For example, in Horvath, the driver could not look
to the Crown for contribution because of a statutory bar.
¶28 Between concurrent tortfeasors, liability is apportioned on the basis of “moral
blameworthiness” rather than the degree to which each tortfeasor contributed to the plaintiff’s
23
Ibid.
Hicks v. Cooper (1973), 1 O.R. (2d) 221 (C.A.).
25
Zylstra v. Hughes, 2001 BCCA 326 [Zylstra].
26
Negligence Act, supra note 15, s. 4(1).
27
Ibid. s. 4(2)(b).
24
8
total damages.28 The factors to be considered by the court in assessing the relative moral
blameworthiness were recently summarized by Mr. Justice Groves in Aberdeen:29
(1) The nature of the duty owed by the tortfeasor to the injured person.
(2) The number of acts of fault or negligence committed by a person at fault.
(3) The timing of the various negligent acts. For example, the party who first commits a
negligent act will usually be more at fault than the party whose negligence comes as
a result of the initial fault.
(4) The nature of the conduct held to amount to fault. For example, indifference to the
results of the conduct may be more blameworthy. Similarly, a deliberate departure
from safety rules may be more blameworthy than an imperfect reaction to a crisis.
(5) The extent to which the conduct breaches statutory requirements. For example, in a
motor vehicle collision, the driver of the vehicle with the right of way may be less
blameworthy.
(6) The gravity of the risk created.
(7) The extent of the opportunity to avoid or prevent the accident or the damage.
(8) Whether the conduct in question was deliberate, or unusual or unexpected.
(9) The knowledge one person had or should have had of the conduct of another
person at fault.
¶29 Considering these factors, the trial judge distributes fault between the concurrent
tortfeasors and apportions damages accordingly. The following passages from Aberdeen
provide a useful example of the link between the factors and the ultimate distribution of
liability:
In relation to Zanatta's negligence, his crossing the centre line was a momentary lapse
in his attention while driving. As Langley observes, many serious traffic accidents are
caused by momentary lapses in attention. A fairly serious risk was created by the
presence of a large cube van within the lane normally occupied by oncoming traffic on a
steep hill with a sharp curve, and this risk could have been completely avoided had
Zanatta exercised proper care while driving. However, Zanatta did not actually strike the
plaintiff, and his fault was due to inattention, rather than being an intentional act.
Therefore, I conclude that Zanatta's conduct represented a moderate departure from
the standard of care expected in the circumstances.
In contrast, I have concluded that Langley's departure from the standard of care was
considerably greater than Zanatta's: while Langley did not intentionally create a hazard,
it knowingly created a serious risk when it decided not to replace the entirety of the
existing guard rail in 1999, or to take measures to ensure that cyclists or cars would not
risk injury due to the existence of a gap between the two guard rails. Langley knew that
28
See Hub Excavating Ltd. v. Orca Estates Ltd., 2008 BCSC 21; Cempel v. Harrison Hot Springs Hotel Ltd.
(1997), 43 B.C.L.R. (3d) 219 ¶19 (C.A.) [Cempel]; Alberta Wheat Pool v. Northwest Pile Driving Ltd., 2000
BCCA 505 ¶46 [Alberta Wheat Pool]; and Aberdeen, supra note 21.
29
Aberdeen, supra note 21 ¶62-63.
9
272nd Street was frequently used by cyclists, and in fact was a designated bicycle route.
Langley had over three years to take action to avoid the risk of injury due to the barrier
configuration. The cost was not prohibitively high, and money could have been allocated
from the existing budget to remedy the situation. The gravity of risk created by Langley's
decision was high, both for cyclists and for cars that might have been redirected by the
metal barrier into a collision with the no-post barrier. The expert witnesses of both the
plaintiff and the Zanatta defendants thought that this gap was obviously "unsafe" and
"constituted a violation of basic traffic safety practices." The departure from the standard
of care expected of a municipality in these circumstances was considerably higher than
Zanatta's departure from the relevant standard of care. Accordingly, I would apportion
liability for the plaintiff's injuries 25% to the Zanatta defendants and 75% to Langley.30
2. Consecutive Tortfeasors
¶30 Having found the tortfeasors to be consecutive, the fifth step is to determine whether
the consecutive tortious events present sufficient or insufficient causes, borrowing this
terminology from Professor McInnes’s paper on causation.31 “Sufficient causes” generally
describes the situation where each incident has caused an injury and their effects have
superimposed on each other, or the second injury was aggravated by the first one:
… cases of "multiple sufficient causation" in which each of the competing causes
independently was capable of producing the loss in question. In such circumstances,
the "but for" test often fails to provide a satisfactory answer. Looking at each factor in
isolation, it cannot be said that the loss would not have occurred "but for" that cause;
even if the first cause had not occurred, the second cause would have created the same
outcome, and vice versa.32
¶31 This is a situation that typically occurs in multiple accident cases, where the plaintiff
recovering from a physical injury suffered in a first accident is involved in a second accident,
where the same injury occurs again. For example, the physical injuries suffered by the
plaintiff in the first accident caused depression and the physical injuries suffered in the
second accident made that depression worse.
¶32 “Insufficient causes” describes the situation where injury was caused only by the
combination of the tortious acts. In other words, the injury is “the result of several causal
factors, all of which were necessary, and none of which independently was sufficient, for its
occurrence.”33 Such injury is not apparent or symptomatic after the first incident. For
example, while neither the first nor the second accident resulted in sufficiently severe
30
Aberdeen, supra note 21 ¶77-78.
Mitchell McInnes, “Causation in Tort Law: Back to Basics at the Supreme Court of Canada”, (1997) 35 Alta. L.
Rev. 1013.
32
Ibid.
33
Ibid.
31
10
physical injuries to cause the plaintiff’s depression, the combination of both was sufficient to
trigger it.
¶33 Once the situation is categorized into sufficient or insufficient causes, the sixth step is
to apply the appropriate apportionment method.
a) Sufficient Causes
¶34 In the case of sufficient causes, the appropriate method for distributing liability and
apportioning damages under s. 4 of the Negligence Act is the subject of some controversy.
There are, of course, numerous cases that dictate that liability is distributed between
tortfeasors based on the “degrees the parties departed from the norm of reasonable
conduct”, rather than based on “the relative degrees of causation”.34 However, all of these
cases involve concurrent tortfeasors and/or contributory liability of the plaintiff, and do not
deal with consecutive tortfeasors.35
¶35 However, Thiessen did apparently deal with a situation involving consecutive
tortfeasors36 and its approach is difficult, if not impossible, to reconcile with the relative
blameworthiness approach. The Thiessen approach is based on a formula which places the
onus of proving how the damages should be apportioned on the second tortfeasor, under the
theory that he or she “made the proof of the plaintiff's damages resulting from the first
accident more difficult”.37 The Thiessen formula involves three steps:
(a) To assess as best one can what the plaintiff would have recovered against the [first
tortfeasors] had his action against them been tried …the day before the second
accident, and to award damages accordingly;
(b) To assess global damages as of the date of the trial in respect of both accidents;
and
34
Cempel, supra note 28 ¶18 and ¶21.
For example, Cempel, ibid, apportioned liability between the plaintiff and the defendant for falling into an
extremely hot pool; Alberta Wheat Pool, supra note 28, apportioned liability between owner and contractor for
negligent act causing a fire; Ottosen v. Kasper (1986), 37 C.C.L.T. 270 (B.C.C.A.), aff’g (1984), 60 B.C.L.R. 164
(S.C.) [Ottosen], apportioned liability between liability between the plaintiff and the two negligent drivers who
caused the accident; Heller v. Martens, 2002 ABCA 122 [Heller], from which Groves J. in Aberdeen summarized
the relevant factors, apportioned liability between the negligent driver, the plaintiff, and plaintiff’s employer who
failed to provide a seatbelt.
36
The nature of the injuries is not entirely clear from the appeal judgment and there are arguments to be made
that they were divisible or indivisible, and caused by sufficient or insufficient causes. Unfortunately, the trial
judgment was not reported and has been lost in the annals of history.
37
Thiessen, supra note 2 ¶48.
35
11
(c) To deduct the amount under (a) from the amount under (b) and award damages
against [the second tortfeasor] in the amount of the difference.38
¶36 The Thiessen formula has been approved in a number of British Columbia decisions
involving consecutive tortfeasors and sufficient causes. In Pryor v. Bains, the British
Columbia Court of Appeal implicitly approved this approach, explaining that apportionment
between aggravating causes is appropriate:
These two sources or causes of damages can be dealt with, either as a case of
aggravated damages or as a "thin skull" case, depending on which of two factual
circumstances are found to exist. In a case where a second source or cause of
damages is found to aggravate an existing and active first source or cause, that is a
case of aggravated damages and there may be an apportionment of damages as
between the two sources or causes.39
¶37 In Zylstra,40 the Court of Appeal affirmed the trial judge’s use of the Thiessen formula to
apportion damages between three tortfeasors liable for three separate accidents which
caused the plaintiff’s back pain. The court referred to Thiessen as the “leading case” on
“apportionment of damages between the accidents.”41 Similarly, in Resvick v. Behan, the
Court of Appeal implicitly agreed with the trial judge giving instructions to the jury based on
the Thiessen formula.42
¶38 Furthermore, the Thiessen approach seems to be congruent with the general principles
of apportioning damages set out in Blackwater, where McLachlin C.J.C. explained that the
plaintiff’s prior condition must be taken into account when assessing damages caused by a
later tortious act:
It is important to distinguish between causation as the source of the loss and the rules
of damage assessment in tort. The rules of causation consider generally whether "but
for" the defendant's acts, the plaintiff's damages would have been incurred on a balance
of probabilities. Even though there may be several tortious and non-tortious causes of
injury, so long as the defendant's act is a cause of the plaintiff's damage, the defendant
is fully liable for that damage. The rules of damages then consider what the original
position of the plaintiff would have been. The governing principle is that the defendant
need not put the plaintiff in a better position than his original position and should not
compensate the plaintiff for any damages he would have suffered anyway: Athey. Mr.
Barney's submissions that injury from traumas other than the sexual assault should not
38
Ibid.
Pryor v. Bains (1986), 69 B.C.L.R. 395 (C.A.). It should be noted, however, that this case was decided before
the distinction between divisible and indivisible injuries was elucidated in Athey and thus it did not treat
apportionment of damages from effectively indivisible injuries as an exercise only between the tortfeasors.
40
Zylstra, supra note 25.
41
Ibid.
42
Resvick v. Behan, 2004 BCCA 166 ¶9.
39
12
be excluded amount to the contention that once a tortious act has been found to be a
material cause of injury, the defendant becomes liable for all damages complained of
after, whether or not the defendant was responsible for those damages.
At the same time, the defendant takes his victim as he finds him -- the thin skull rule.
Here the victim suffered trauma before coming to AIRS. The question then becomes:
what was the effect of the sexual assault on him, in his already damaged condition? The
damages are damages caused by the sexual assaults, not the prior condition. However,
it is necessary to consider the prior condition to determine what loss was caused by the
assaults. Therefore, to the extent that the evidence shows that the effect of the sexual
assaults would have been greater because of his pre-existing injury, that pre-existing
condition can be taken into account in assessing damages.43
¶39 While Blackwater involved divisible injuries arising from the actionable torts before the
court and previous non-tortious or non-actionable causes, the same general principle of
justice from the perspective of both the victim and the tortfeasor applies here. The moral
blameworthiness approach does not explain why, in the case of sufficient causes, it would be
just to have one consecutive tortfeasor be responsible for the damage that he or she did not
cause simply because his or her negligence causing one of the accidents can be said to have
departed further from the standard of care than the negligence of the other consecutive
tortfeasor who caused the other accident.
¶40 However, Thiessen has been criticized for the perceived unfairness of its approach. In
Civil Jury Instructions, the authors summarized the criticism as follows:
For a critique of this method of assessment see Cooper-Stephenson, Personal Injury
Damages in Canada, 2nd ed. (1996), at 906-907. It is argued that where the plaintiff
was involved in two separate accidents and the second aggravates the first, application
of the Long v. Thiessen method of apportionment may cause hardship because it
essentially treats the second accident as a novus actus. In other words, this method
does not fairly apportion liability if both accidents were “necessary” to produce some of
the loss. The authors use the example of an accident causing the plaintiff to lose sight in
one eye, resulting in a diminished earning capacity of 10%. If he loses the other eye in a
second accident, his earning capacity would likely disappear. However, using the Long
v. Thiessen analysis, the first defendant would be only 10% liable, when in reality, the
total disability was jointly caused by both defendants.44
¶41 In Ashcroft, Mr. Justice Shaw was similarly concerned that applying Thiessen in a case
involving a plaintiff injured in two accidents but only suing the tortfeasor liable for the first,
43
Blackwater, supra note 1 ¶78-79, emphasis added.
Bouck et al., Civil Jury Instructions, looseleaf (Vancouver, B.C.: The Continuing Legal Education Society of
British Columbia) at 9-61.
44
13
would “confine the assessment to the injuries suffered in the first accident only, and not
include those suffered in the second accident.”45
¶42 With respect, these criticisms appear to be misplaced. If both accidents were necessary
to produce the injury, then it is an indivisible injury for which both consecutive tortfeasors are
jointly and severally liable. As discussed above, this is so whether both incidents were
necessary to produce the injury (insufficient causes), or the injury could have been produced
by either incident, the effects of which superimposed on each other (sufficient causes). The
Thiessen formula is then used only to apportion liability and damages between the
tortfeasors. It does not affect compensation to the plaintiff.
¶43 Notwithstanding the logic and policy behind the Thiessen approach and the case law
which apparently approves it, the most poignant problem with using Thiessen to apportion
liability and damages between consecutive tortfeasors is that s. 4 of the Negligence Act
speaks only in terms of relative degrees of fault and 4(2)(b) apportions liability based on
those degrees:
4(1) If damage or loss has been caused by the fault of 2 or more persons, the court
must determine the degree to which each person was at fault.
(2) …
(b) as between themselves, in the absence of a contract express or implied, they
are liable to contribute to and indemnify each other in the degree to which they are
respectively found to have been at fault.46
¶44 A possible rationale for the Thiessen approach is that it allows the determination of
degrees of fault via the proxy of damages. Causation (liability) and damages are inherently
interrelated, and the law of torts knows of other situations where the former is determined
through the latter. For example, in Newton v. Marzban,47 Madam Justice Nielson, relying on
Hagblom v. Henderson,48 explained that in the cases involving a lawyer’s negligent conduct of
a trial, the plaintiff’s chance of obtaining a favourable outcome – generally evaluated as part
of quantification of damages, must be evaluated to determine whether the plaintiff has lost
something of value – i.e., has proven causation. This suggests that where liability cannot be
determined directly, it can be determined via the proxy of analyzing damages.
45
Ashcroft, supra note 6 ¶25.
Negligence Act, supra note 15.
47
Newton v. Marzban, 2008 BCSC 328 ¶754-760.
48
Hagblom v. Henderson, 2003 SKCA 40.
46
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b) Insufficient Causes
¶45 There appear to be no cases that specifically deal with the appropriate method of
apportioning liability in this scenario. However, it would appear that the choice of applicable
method is mostly practical rather than principled. Specifically, the Thiessen approach is prima
facie inapplicable because the injury was not symptomatic or the damages not apparent
before the second accident, at which point the effects combined. Strict application of the
Thiessen formula would place the whole of the burden on the second tortfeasor – unjustly so.
While the Thiessen approach is impractical, the moral blameworthiness approach may be
subject to the same criticism as above in the context of sufficient causes. Specifically, why
should tortfeasors responsible for entirely separate and unconnected events be compared to
each other in terms of their relative departures from the applicable standard of care.
¶46 Nevertheless, given that the available menu of these two methods, the only applicable
one is the moral blameworthiness approach. While arguments could conceivably be made to
give this choice some principled validity, lack of alternatives seems to present the most
persuasive reason.
c) Combination of Sufficient and Insufficient Causes
¶47 As described in the introductory example, situations that come before the courts are
often quite complex enough to transcend the categories described in this paper.
Unfortunately, case law provides even less authority on apportioning damages in such
combinations of events than it does for apportioning damages within the categories described
in this paper. However, it is suggested that the approaches discussed above can be relatively
easily adapted for such complex situations.
¶48 For example, an indivisible injury may have been caused by consecutive accidents,
each presenting a sufficient cause, and one or more of which these accidents was also
caused by two or more concurrent tortfeasors. Applying the approaches already discussed, it
is suggested that the appropriate course of action is first to apportion liability (and damages)
between the accidents using the Thiessen formula, and then apportion liability between each
set of concurrent tortfeasors using the blameworthiness approach.
B. Contributory Negligence
¶49 As discussed above, where the trial judge determines that the plaintiff was contributorily
negligent in one or more tortious events that caused the indivisible injury in, ss. 1 and 2 of the
15
Negligence Act become applicable and the plaintiff can only recover from each tortfeasor “the
percentage of the damage or loss sustained that corresponds to the degree of fault of that
other person”.49 As the British Columbia Court of Appeal noted in Laing Property Corp. v. All
Seasons Display Inc.,
It is now settled law in British Columbia that s. 1 of the Negligence Act only applies
where the plaintiff is found to be contributorily negligent for its own losses. In such
circumstances, liability between two or more tortfeasors is several, not joint, and there is
therefore no basis for third party claims for contribution or indemnity.50
¶50 Thus, the next task of the trial judge is to apportion damages between the tortfeasors
and the plaintiff. However, the fourth step is still to determine whether the injuries resulted
from concurrent or consecutive causes.
¶51 The concepts of concurrent and consecutive causes are very similar to the previously
described concepts of concurrent and consecutive tortfeasors. In particular, concurrent
causes refer to injuries caused by concurrent tortfeasors together with a contributorily
negligent plaintiff, and consecutive causes refer to injuries caused (directly or by material
contribution) by consecutive tortfeasors together with a plaintiff who is found to have been
contributorily negligent in at least one of the tortious events. There are two chief factors
distinguishing the two sets of terms. First, the plaintiff, even if contributorily negligent, cannot
be considered a tortfeasor. Thus, using the term concurrent tortfeasors can be misleading
with respect to the contributorily negligent plaintiff. Second, the general approach to
apportioning liability between multiple tortfeasors and a contributorily negligent plaintiff,
elucidated by Bastarache J. in Ingles, treats the tortfeasors and the plaintiff differently and
accordingly dictates a two step approach to apportionment:
When there are two or more tortfeasors, and a plaintiff has also been found negligent,
the proper approach to apportionment is to first reduce the extent of the recoverable
damages in proportion with the plaintiff's negligence, and then to apportion the
remaining damages between the defendants, in accordance with their fault …51
1. Concurrent Causes
¶52 Where the trial judge determines that that the injury was cased by concurrent causes,
the fifth step is to apply the moral blameworthiness method to apportion liability between the
tortfeasors and the plaintiff. Then, in accordance with the Ingles approach, the total damages
49
50
Negligence Act, supra note 26, s. 2(c).
Laing, supra note 16 ¶76, authorities omitted.
16
are reduced by the plaintiff’s liability and the remainder is apportioned between the
tortfeasors on the basis of their liability. For an example of this type of apportionment see
Ottosen, where liability was apportioned between the infant plaintiff and the two negligent
drivers who caused the accident.52
2. Consecutive Causes
¶53 The previous discussion of consecutive tortfeasors is generally applicable to the
situation of consecutive causes as well. Thus, the sixth step is to determine whether the
injury resulted from sufficient or insufficient causes.
a) Insufficient Causes
¶54 In the case of insufficient causes, liability should be apportioned using the moral
blameworthiness technique between the tortfeasors and the contributorily negligent plaintiff,
as it would be apportioned been between just consecutive tortfeasors. In the apportionment
of liability, the plaintiff is considered as merely another tortfeasor. However, the Ingles
treatment of the plaintiff then applies for apportioning damages.
b) Sufficient Causes
¶55 In the case of sufficient causes, logic dictates damages should first be apportioned
between the consecutive events (causes) using the Thiessen formula, and then apportioned
between the parties responsible for each event, including the plaintiff if contributory
negligence is found. The apportionment of liability and damages within each event is done on
the basis of the moral blameworthiness approach as between concurrent tortfeasors.
¶56 Importantly, Blackwater appears to implicitly support using the Thiessen approach for
apportioning damages between consecutive sufficient causes. This proposition is best
explained by the way of two examples.
¶57 First, consider two consecutive events whereby the plaintiff is 100% responsible for the
first and the defendant is 100% responsible for the second. The damages in the first accident
are relatively minor, such that the bulk of damages really results on the second accident. In
this situation, Blackwater dictates that the defendant is liable to compensate the plaintiff to
restore him to the position he was in immediately before the tort. No relative blameworthiness
51
52
Ingles, supra note 16 ¶55.
Ottosen, supra note 35.
17
is assessed and damages are effectively apportioned between the plaintiff and the defendant
on the basis of relative causation. The plaintiff is fully compensated for the effects of the
second accident. Implicitly, this illustrates the application of the Thiessen formula, whereby
the onus is on the defendant to prove the state that the plaintiff was in at the time of the tort.
¶58 Now, consider a situation of the same two consecutive accidents, but this time the
responsibility for the first one is shared between the plaintiff and a tortfeasor. Applying the
moral blameworthiness approach to assess fault between the plaintiff and the two tortfeasors,
as would be prescribed by the insistence on assessing degrees of fault in all contributory
negligence situations, the plaintiff is found to have been 30% at fault, the first tortfeasor 20%,
and the third tortfeasor also 50%. However, as the bulk of the damages were resulted from
the second accident, the plaintiff now recovers only approximately 70% of the damages.
Paradoxically, applying the moral blameworthiness approach in this case, although the
plaintiff is less at fault in the second than in the first scenario, where he was 100%
responsible for the first accident, he now recovers less damages. There appears to be no
rational policy or practical explanation for why this should be so.
IV. Divisible Injuries
¶59 Going back to the second step, if the trial judge determines that the plaintiff’s injuries
are divisible, the third step is to identify each claimed head of damages. As will be seen
below, the reason why apportionment has to be done separately for each head of damages is
because the actual effects from the divisible injuries may be distinct – to be compensated
under a specific head of damages, or combine – requiring compensation under the same
head of damages as effects from another injury. For example, consider a case of two divisible
injuries arising from two separate incidents: depression and a broken arm. While the effects
of both the depression and the broken arm are compensated in the award for non-pecuniary
damages, only the broken arm has resulted in the loss of wages.
¶60 Once the head of damages is identified, the fourth step is to determine whether the
effects of the divisible injuries claimed under this head of damages represent discrete or
superimposed effects.
A. Discrete Effects
¶61 Where the effects are discrete, the damages claimed under a specific head were either
only caused by a specific divisible injury or were caused by one divisible injury, fully abated,
18
and then were again caused by another divisible injury. In either case, there is no overlap of
effects. In this case, the trial judge uses the traditional rules for quantification of damages to
assess the damages under the claimed head. In effect, no apportionment is done here.
¶62 A partial example of this approach can be found in Hutchings, where Mr. Justice Cullen
was able to separate special damages arising from the accident and the assault.53 Similarly,
in McNaughton, the trial judge found that the divisible injuries caused by the accident did not
cause the plaintiff any “past loss of employment income, future loss of employment income,
loss of future earning capacity after retirement, net loss of future pension income, loss of
Public Service Award, loss of employer paid fringe benefits, loss of future valuable services,
[and] future cost of care”, which were caused by the subsequent workplace injury, and
dismissed claims under those heads of damages.54
B. Superimposed Effects
¶63 In the case of superimposed effects, losses under a head of damages represent the
combined effects of two or more divisible injuries. Considering the example of a broken arm
and a broken leg provided by Mr. Justice Major in Athey, both divisible injuries are
compensable under the head of non-pecuniary damages. Moreover, if the second accident
occurred while the injury from the first accident was still healing, the effects were
superimposed on each other for at least a period of time. Assuming that Thiessen involved a
divisible injury,55 then the following passages from the headnote and the judgment describe
the situation of superimposed effects:
[headnote]
As a result of the first accident he suffered considerable pain, discomfort and limitation
of movement, was subject to frequent headaches and dizzy spells and became irritable
and depressed. Up to the day before the second accident respondent was beginning to
show some improvement in his general condition although many of the earlier
symptoms were still present. As a result of the second accident there was a marked
degeneration in his condition….
[judgment]
53
Hutchings, supra note 14 ¶393-94.
McNaughton, supra note 13, trial decision, ¶97.
55
Supra note 36.
54
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Because the injuries inflicted in the second accident were superimposed upon the then
residual effects of the injuries inflicted in the first accident, it is a matter of the greatest
difficulty to determine what damages should be awarded for each set of injuries.56
¶64 In such situations, Thiessen seems to provide the only reasonable approach for
apportioning damages between the tortfeasors. Pursuant to its formula, the onus is placed on
the second tortfeasor to prove the damages that the plaintiff was suffering at the time of the
first accident. The damages apportioned to the second tortfeasor are the difference between
the overall damages that the plaintiff is suffering at the time of the trial and the damages
found to have been caused by the first tortfeasor. Where there were more than two
tortfeasors, the same formula may be applied with iteration. Thus, if there were three
tortfeasors, the onus is first placed on the third to establish the damages at the time of the
second accident. Then, the onus is placed on the second tortfeasor to establish damages at
the time of the first accident.
¶65 If the plaintiff is found to have been contributorily negligent for one or more of the
accidents, then the apportionment of damages between the plaintiff and the tortfeasor(s)
takes place once the damages attributable to that accident are identified. This approach
conforms with the Negligence Act as only the injuries suffered in a specific accident are
indivisible injuries to which the defendant may seek contribution.
V.
Conclusion
¶66 In summary, this paper proposes the following steps for apportioning damages based
on a hierarchical taxonomy of cases:
1
Assess injuries suffered;
2
Determine whether the injury is divisible or indivisible;
2.1
If indivisible, determine if there was contributory negligence by plaintiff;
2.1.1
If no contributory negligence, the tortfeasors are jointly and severally liable and
apportionment only matters as between the tortfeasors, determine whether the
tortfeasors are concurrent or consecutive;
2.1.1.1
If concurrent, apportion liability based on moral blameworthiness and
apportion damages accordingly;
56
Thiessen, supra note 2 headnotes and ¶47.
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2.1.1.2
If consecutive, determine whether the events presented multiple sufficient or
insufficient causes;
2.1.1.2.1 If insufficient, apply the moral blameworthiness approach;
2.1.1.2.2 If sufficient, apportion damages and liability using the Thiessen formula;
2.1.2
If there is contributory negligence, the tortfeasors are only liable to the extent
of their fault, determine whether the causes were concurrent or consecutive;
2.1.2.1
If concurrent, apportion damages using the moral blameworthiness approach;
2.1.2.2
If consecutive, determine whether the events presented multiple sufficient or
insufficient causes;
2.1.2.2.1 If insufficient, apportion damages using the moral blameworthiness approach;
2.1.2.2.2 If sufficient, first apportion damages between events using the Thiessen
formula and then apportion damages for each event between the plaintiff and
the tortfeasor(s) liable for it using the moral blameworthiness approach
2.1.3
If divisible, proceed with separate apportionment for each head of damages;
2.1.4
for each head of damages, determine whether the injuries caused discrete or
superimposed effects;
2.1.4.1
If discrete, assess specific effects caused by each injury and apportion
damages accordingly;
2.1.4.2
If superimposed, use the Thiessen formula to apportion damages between
tortfeasors.
¶67 Naturally, there may be other situations which were not addressed in the above
taxonomy. However, with the applicable principles identified for the above situations, it is
hoped that this provide guidance for new scenarios that may come up on facts of particular
cases.
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