other than to the parties and their representatives?
(Rev'd June 30 by adding numbered points 2-9 n the Brief Summary of Consequences, the heading, and the underlined phrase in the next sentence)
It will, but it will not help plaintiffs other than Ms. Clements.
Appeal allowed and sent back for a new trial by a majority decision (7-2). The Court was unanimous on the law, just not the remedy.
Brief Summary of Consequences
1. Overall, I think what the reasons mean is that there won't be a change in the practice in the common law jurisdictions in Canada as it has developed over the past few years, beyond seeing more references to "common sense" inferences. Whatever "common sense" means, if it means anything more than valid (by whatever rules apply to determine when an inference is a valid inference), is a mystery for another day.
2. It's my belief, from reported cases over the past 5 years, that the demise of Athey material contribution, in practice, hasn't reduced the chance of plaintiff' success. My belief is that all that happened was a change in judicial terminology. I think the directions in Clements as to how the but-for test is to be applied will cement this change. I am not suggesting that any judge stated that the judge had made a but-for finding of fact when the judge actually applied his or her understanding of Athey because the judge thought that the but-for test was "unworkable". I am stating that I can't discern any relevant change in the content of the analysis in those cases where it is reasonable to suspect that, before Resurfice, a trial judge would have used Athey material contribution.
3. To establish factual causation in a cause of action in negligence, the plaintiff will have to use, and satisfy, the but-for test, except in claims arising out of the negligent screening of blood donors. Clements did not overrule Walker Estate. Cook v. Lewis is likely still alive, too.
4. It necessarily follows, although the the Supreme Court did not explicitly say this so, that Athey material contribution, whatever it meant before 2007 as a method for establishing factual causation on the balance of probability, is as dead as the proverbial Monty Python Norweigian blue parrot.
5. The British Columbia Court of Appeal won the undeclared, unacknowledged, contest between some of its judges and some Ontario Court of Appeal judges over the meaning of Resurfice material contribution. That doctrine, whatever else it means, is NOT an alternative method for establishing factual causation on the balance of probability. That means Resurfice did more than merely clarify the Canadian law on proof of causation in negligence. It changed the content. Resurfice material contribution is a "material contribution to risk" doctrine. (See items 8 and 10).
6. Clements, for now, narrows the scope of the Resurfice material contribution doctrine from that which seemed to follow from the text of Resurfice. Among other reasons is that Clements states, explicitly, that the doctrine requires two or more tortfeasors. (Some of you may wonder how this can be when the second example in Resurfice of when the doctrine might apply does not require two negligent wrongdoers. If the donor had been negligent, that generally would not have provided the CRCS a defence. A blood donor could be negligent merely through misunderstanding the guidelines. However, the definition of intention in tort is such that the donor would still be negligent even if the donor intentionally ignored the guidelines, so long as the donor's belief that the donor's blood was not infected was objectively reasonable. However, one could argue that the "legal chain of causation" might have been "broken" if the evidence had been that the donor intentionally ignored the CRCS's guidelines when donating, knowing that the guidelines meant the donor wasn't supposed to donate. That argument becomes stronger if the ought to have known the blood donor's blood was infected; even stronger if the donor was reckless – didn't care one way or the other; and stronger yet if the donor knew. (Added July 5, 2012)).
7. It is even clearer that "fairness and justice" is a third precondition for the use of Resurfice material contribution; "fairness and justice" is not established merely by satisfying the impossibility and ambit of risk requirements; and it seems the plaintiff has the onus of proof on the fairness and justice requirement, too.
8. In those jurisdictions where jury trials are still available in civil actions – both the issue of whether the Resurfice material contribution test is applicable and the issue of whether the plaintiff has satisfied the requirements of the doctrine will have to be decided by a judge. Whether that means that, in practice, there can't be a jury to decide ONLY relevant questions of fact, in a case where the ONLY theory of causation the plaintiff alleges is Resurfice material contribution, is something some judge will have to sort out in due course. Plaintiffs' counsel who want that alternative should consider having a detailed list of questions that the jury will be asked to answer.
9. We still do not know whether the extent of liability, in cases where Resurfice material contribution does apply, is just proportional (several) or joint and several. Clements is silent on this issue. That can't have been an oversight.
10. Have fun (?) (billable time?) (wasted time?) speculating on what "material" and "contribution" mean in the phrase "material contribution to risk" if the terms mean anything other than "significant enough" and "a cause of", so that the phrase means something like "a sufficient enough cause of the unreasonable increase in risk which is what made the defendant's conduct negligent, in the first place." That's because merely increasing risk isn't the definition of negligence and, without negligence, one never, ever, gets to causation issues.
10. There are probably more than 10 Commandments in Clements, too.
While the Court did not explicitly say this, Athey material contribution is defunct as an alternative method for proof of factual causation on the balance of probability. However, there is no indication, from the result of cases over the past 5 years, that this has reduced the chances of plaintiffs succeeding. Given what the Supreme Court said in Clements about how the but-for test is to be used, I don't see any room left for any use of the Athey version as it was used before Resurfice. of a material contribution plaintiff has not affect plaintiffs if, as appears from the practice over the past 5 years, whatever it was that that Athey material contribution test meant, once upon a time, as an alternatimy conclusion is correct that has happened over the past 5 years is that trial judges
The majority held the but-for test was the applicable test but the trial judge's errors of law were such that the Court couldn't decide what he would have done, on his findings of fact, had he applied the law correctly.
 We cannot be certain what the trial judge would have concluded had he not made the errors I earlier described. All that can be said is that the parties did not receive a trial based on correct legal principles. In my view, the appropriate remedy in these circumstances is an order for a new trial.The Court was unanimous on the law.
The dissenting judges would have dismissed the appeal becuase they disagreed with the majority's view of the trial judge's findings of fact. The dissent wrote at 
that they were "unable to find any basis in the trial judge’s judgment for inferring that …[ the defendant's negligence ] …. could have been the “cause” of the accident as that term is understood in the context of the “but for” test. Nor is this a case in which it would be appropriate to send the matter back for a new trial."
For the law:
Resurfice material contribution is a "material contribution to risk" doctrine. (No, the court did not explain what "material" means.) While the SCC rejected the details of the Clements analysis of Resurfice material contribution, the SCC seems to have accepted the BCCA explanation that Resurfice material contribution is not a test for factual causation but a policy – based approach that, in certain circumstances, will permit the courts to hold the caausation requirements of the cause of action have been satisfied notwithsanding that factual causation has not been established on the balance of probability.
The Court provided some explanation of what "impossibility" means in the Resurfice material contribution test.
The Court seems to have provided somewhat of a roadmap for proof of causation where there are multiple sufficient causes and multiple tortfeasors.
 It is important to reaffirm that in the usual case of multiple agents or actors, the traditional “but for” test still applies. The question, as discussed earlier, is whether the plaintiff has shown that one or more of the defendants’ negligence was a necessary cause of the injury. Degrees of fault are reflected in calculations made under contributory negligence legislation. By contrast, the material contribution to risk approach applies where “but for” causation cannot be proven against any of multiple defendants, all negligent in a manner that might have in fact caused the plaintiff’s injury, because each can use a “point the finger” strategy to preclude a finding of causation on a balance of probabilities
I'll do no more, now than point out a seeming problem in the last sentence. As written, it covers what is called duplicative causation – where there are multiple separate causes, not multiple cumulatively necessary causes. In duplicative causation, each cause is a factual cause. Each of the duplicative causes is a factual cause even though the but-for test can't be used.
We must not forget that there was a seriously injured person who will be able to use the proceeds of a a win to better pay for her future care. If the plaintiff succeeds, payment will come (up to policy limits) from the insurance company of the defendant. (Here, that insurance company is, ultimately, the province of British Columbia – meaning B.C. taxpayers in a sense) but the injured person's need and the defendant's ability to pay are not supposed to be relevant to the decision in a tort action. I think it is safe to say that the Supreme Court will not decide the case based on the ability of the defendant to pay, even if he has insurance. (See Dobson (Litigation Guardian of) v. Dobson,  2 SCR 753, 1999 CanLII 698.
The Clements decision could matter depending on how the SCC decides the case. That statement isn't quite as trite as it seems.
The SCC might decide the case only on very narrow grounds – essentially that the but-for test governed and the facts were or were not sufficient – and state it's not to taken as agreeing or disagreeing with anything the BCCA said about Resurfice material contribution. Clements won't advance the jurisprudence if it is decided on that basis, beyond the message it sends to the lower courts that the SCC meant "exceptional" (whatever that means) when it said, in Resurfice, that Resurfice material contribution applies only in exceptional cases. That's not out of the realm of plausibility (as opposed to possibility) because the SCC has granted leave in another case which the Court might consider provides a better platform for discussing causation issues Ediger v. Johnston SCC case # 34408. That case is scheduled for argument in December 2012.
It's an easy argument to make that there is nothing exceptional most a single vehicle motor vehicle accidents where the narrow issue is why the driver lost control or couldn't regain control, or both. An argument has been made – for example, in Lynda M. Collins “Causation, contribution and Clements: Revisiting the material contribution test in Canadian tort law” (2011), 19 Tort L. Rev. 86 - that there is something inherently uncertain about vehicle dynamics because (in the scheme of human scientific progress) this subject is relatively new. My suspicion is that the courts will be resistant to that argument.
The following is a bit of a "how we got to this stage summary" for those who care.
1. Between late 1996 and early 2007, Canadian negligence law had two tests for proof, on the balance of probability, of factual causation. In negligence factual causation is supposed to ask the question: was the defendant's negligence a cause of the plaintiff's injury.
2. One test was labelled the "but-for" test. The other the Athey v. Leonati "material contribution" test.
3. While we never had an adequate judicial definition (actually we never had any definition) of Athey material contribution, we had a Supreme Court of Canada statement about when Athey material contribution was to be used. According to Athey, the Athey material contribution test was to be used when the but-for test was "unworkable".
4. But Athey did not define what "unworkable" meant and the cases it cited as as authorities for the existence of the material contribution test did not, either.
5. The Supreme Court of Canada did not return to the meaning of Athey material contribution until 2007 in Resurfice in February2007.
6. However, in 2001, in Walker Estate the SCC discussed another version of a material contribution test applicable only to causes of action arising out of the negligent screening of blood donors. Many subsequent lower court decisions ignored this, citing both Walker Estate and Athey as the authority for use of the material contribution test rather than the but-for test. Keep this in mind. It becomes important when we reach Resurfice. (There are other reasons why Walker Estate material contribution was not an application of Athey material contribution but they're not relevant here.)
7. In the interregnum – the 1996 – 2007 many judges at the trial and appellate levels decide the factual causation issue in the plaintiff's favour applying their understanding of Athey material contribution. Sometimes the judges said the but-for test was unworkable and attempted to explain why; sometimes the merely said it was without explaining why; and sometimes there was no mention at all of why the judge was using Athey material contribution rather than the but-for test. But, in the latter cases, at least once we'd reached the late 1990s, trial judges could have pointed to appellate cases as authority for their use of Athey material contribution.
8. Regardless of what the law was supposed to be, what was becoming clear (enough) by 2o05 that Athey material contribution was regularly used, at least by trial judges, used whenever the facts upon which the factual causation decision was to be made became complex. It would not have been wrong to say that Athey material contribution was becoming the default test for plaintiffs' counsel, perhaps even some judges.
9. That wasn't supposed to be what the law was, taking Athey at face value, but most cases never reach trial.
10. Plaintiff's counsel preferred Athey material contribution because it seemed to be easier to use, successfully, than the but-for test.
11. There were some appellate decisions which should have caused judges to rethink how they were using Athey material contribution. For example, in Cottrelle v. Gerrard, in 2003, the Ontario Court of Appeal wrote
 The “but for” test has been relaxed as “unworkable” in cases where, practically speaking, it is impossible to determine the precise cause of the injury. In Athey, for example, the Supreme Court affirmed the “material contribution” test as a qualification to the strict “but for” test only when used in cases similar to Bonnington Castings Ltd. v. Wardlaw, supra, and McGhee v. National Coal Board, supra.
but that didn't happen.
12. What happened was that trial judges and appellate judges (and therefore lawyers in practice) used Athey material contribution, even in cases where the precise cause of the injury was known. It was used to decide the questions: (1) was the defendant's negligence a material part of the cause. That probably meant necessary part of the cause. We'll ignore, for today (g) the questions of how the judges decided if the negligence was a "necessary part" if they could not use the but-for test (because it was "unworkable") and what "material" adds to the question of "did this cause that". "Material" might mean something to the question "should law impose liability" but that's not part of the question "did this cause that".
13. That brings us to 2005 and the Alberta Court of Appeal decision in Resurfice. Recall I said we'd get back to Walker Estate. The ABCA wrote:
 In Athey v. Leonati, 1996 CanLII 183 (SCC),  3 S.C.R. 458, Major, J. stated (at para. 15):
“The ‘but for’ test is unworkable in some circumstances, so the courts have recognized that causation is established where the defendant’s negligence ‘materially contributed’ to the occurrence of the injury.”
 Where there is more than one potential cause, the “material contribution” test should be used: Walker Estate v. York Finch General Hospital, 2001 SCC 23 (CanLII),  1 S.C.R. 647 at 679-680. As the Appellant’s act of inserting or leaving the hose in the gasoline tank may have contributed, the “material contribution” test should have been used. The “but for” test was unworkable in these circumstances.
That reference to Walker Estate is an accurate enough paraphrase of a sentence in Walker Estate, but it ignores the context. The ABCA did not quote the passage. This is the reference, in context. I've marked the sentence the ABCA was referring to in bold.
 With respect to negligent donor screening, the plaintiffs must establish the duty of care and the standard of care owed to them by the CRCS. The plaintiffs must also prove that the CRCS caused their injuries. The unique difficulties in proving causation make this area of negligence atypical. The general test for causation in cases where a single cause can be attributed to a harm is the “but-for” test. However, the but-for test is unworkable in some situations, particularly where multiple independent causes may bring about a single harm.
The SCC wrote in the next paragraph:
 In cases of negligent donor screening, it may be difficult or impossible to prove hypothetically what the donor would have done had he or she been properly screened by the CRCS. The added element of donor conduct in these cases means that the but-for test could operate unfairly, highlighting the possibility of leaving legitimate plaintiffs uncompensated. Thus, the question in cases of negligent donor screening should not be whether the CRCS’s conduct was a necessary condition for the plaintiffs’ injuries using the “but-for” test, but whether that conduct was a sufficient condition. The proper test for causation in cases of negligent donor screening is whether the defendant’s negligence “materially contributed” to the occurrence of the injury. In the present case, it is clear that it did. “A contributing factor is material if it falls outside the de minimis range” (see Athey v. Leonati, 1996 CanLII 183 (SCC),  3 S.C.R. 458, at para. 15).
15. The Supreme Court did not explain, in Walker Estate, what it meant it meant by "multiple independent causes". Nor did it, after, unless we read between the lines of the Court's Resurfice reasons.
16. The ABCA did not explain, in its reasons in Resurfice, why the ABCA claimed the but-for test was "unworkable in these circumstances". But, of course, the ABCA did not have to because Walker Estate said it was, if the sentence in para. 87 of Walker Estate was meant to be taken literally and applied. The explosion that caused the injury in Resurfice was made up of of multiple independent causes (read prior events) all of which were necessary for the explosion to have occurred. There was a single harm: the injury. The ABCA did not explain, though, why it ignored the clear (enough) direction in this paragraph of Walker Estate, and elsewhere in the Walker Estate reasons, that the version of material contribution the SCC was discussing was limited to cases arising out the negligent screening of blood donors. Had the point been made to the ABCA, perhaps the response would have been something like: "the point in the last sentence of para. 87 is a general statement about when the but-for test is "unworkable", hence applicable to all cases where the but-for test is to be applied.
17. In a late 2006 Ontario Court of Appeal decision, Aristorenas v. Comcare Health, the majority of the ONCA panel wrote:
 Athey, however, provides little guidance as to when the “but for” test is unworkable and ought to be replaced by the “material contribution” test. However, Sharpe J.A. examined the type of cases that warrant the adoption of the test at para. 30 of Cottrelle:
 Thus, it would seem that the “material contribution” test is applied to cases that involve multiple inputs that all have harmed the plaintiff. The test is invoked because of logical or structural difficulties in establishing “but for” causation, not because of practical difficulties in establishing that the negligent act was a part of the causal chain.
I suspect that the dissenting judge agreed with this statement of the law.
18. In any event, as of late 2006, most lawyers acting for defendants would have suggested the last sentence of para. 53 of Aristorenas wasn't an accurate description of what was going on in the trial courts.
19. In February 2007, the SCC released its Resurfice reasons. This is what the Court had to say about the ABCA's use of Athey material contribution. It had to be Athey material contribution since Resurfice was not a case arising out of the negligent screening of blood donors.
 The Court of Appeal found, correctly, that the trial judge had applied a “but for” test in determining causation, stating, “[t]he thrust of the reasoning is that ‘but for’ the Appellant putting or leaving the hose in the gasoline tank, the explosion would not have occurred” (para. 12). Referring to the observation in Athey v. Leonati, 1996 CanLII 183 (SCC),  3 S.C.R. 458, at para. 15, that the “but for” test “is unworkable in some circumstances”, the Court of Appeal concluded that this was such a case and that the trial judge should have used a “material contribution” test instead of the “but for” test (para. 14).
 The Court of Appeal erred in suggesting that, where there is more than one potential cause of an injury, the “material contribution” test must be used. To accept this conclusion is to do away with the “but for” test altogether, given that there is more than one potential cause in virtually all litigated cases of negligence. If the Court of Appeal’s reasons in this regard are endorsed, the only conclusion that could be drawn is that the default test for cause-in-fact is now the material contribution test. This is inconsistent with this Court’s judgments in Snell v. Farrell, 1990 CanLII 70 (SCC),  2 S.C.R. 311; Athey v. Leonati, at para. 14; Walker Estate v. York Finch General Hospital, 2001 SCC 23 (CanLII),  1 S.C.R. 647, 2001 SCC 23, at paras. 87-88, and Blackwater v. Plint, 2005 SCC 58 (CanLII),  3 S.C.R. 3, 2005 SCC 58, at para. 78.
Para. 18 isn't quite complete, is it? The ABCA didn't just rely on Athey. The ABCA relied on Walker Estate to explain what "unworkable meant".
20. If the ABCA was correct in taking the last sentence of para. 87 of Walker Estate to be a statement of general application – I'll quote it again -
However, the but-for test is unworkable in some situations, particularly where multiple independent causes may bring about a single harm.
then that statement of law was binding on the ABCA. (It's lower down the pecking order.) But the SCC doesn't mention that in para. 18, or even para. 19, where the SCC stated that the ABCA's reasons were inconsistent with Walker Estate. Indeed one would never know, just from reading Resurfice that the ABCA had relied on Walker Estate.
21. The SCC was, and is, correct in stating that if the ABCA's view was correct, the Athey material contribution test, as the ABCA understood it, had become the default test for proof of factual causation on the balance of probability in negligence actions.
22. So the SCC, in Resurfice, decided that the but-for test governed the facts of Resurfice and reinstated the trial decision. It could have stopped there, but it didn't. The Court went on to discuss the principles of what the Court described (again) as a "material contribution" test without formally explaining how this explanation related to the decade of Athey material contribution jurisprudence (whatever that jurisprudence meant.)
23. We haven't had - putting aside the time after February 2007 that it took for Resurfice to settle in cases where trial judges have formally decided the factual causation issue relying on Athey material contribution. Judges are now formally using the but-for test. (Some of you may conclude, as I have, that in practice it's sometimes just semantics, but we'll put that aside).
24. We also haven't seen any cases where a judge said that he or she, before Resurfice, would have found the factual causation issue in favour of the plaintiff using Athey material contribution – finding factual causation on the balance of probability – but, as a result of Resurfice, is now required to use the but-for test and, on the facts, must find the plaintiff failed to establish factual causation on the balance of probability.
25. We've seen only one case where a trial judge seems to have admitted that, before Resurfice, he'd have used Athey material contribution not but for. He had found the plaintiff had established factual causation applying the but-for test. See Frazer v. Haukioja, 2008 CanLII 42207 (Ont. S.C.J.) at para. 214 (use of Athey material contribution) and para. 217 (plaintiff satisfied the requirements of but-for).
26. This may now be semantics in British Columbia, at least until the SCC rules otherwise or the BCCA reconsiders, because the BCCA has held, in substance, that a but-for cause is a a cause which "materially contributes". For the current summary of that view, see Farrant v. Laktin, 2011 BCCA 336 at paras. 8-11. And, to make matters "curiouser", the BCCA has also held that "materially contributes" means whatever it is that "substantial connection" means, as "substantial connection" as substantial connection was used in Resurfice at para. 23. For the current summary of that view, see Farrant v. Laktin 2011 BCCA 336 at paras. 8-11. The BCCA wrote:
 In Resurfice Corp. v. Hanke, 2007 SCC 7 (CanLII), 2007 SCC 7, 1 S.C.R. 333, the Supreme Court affirmed the “but for” test remains the basic test for determining causation, but developed the concept of “material contribution” in a different manner than that used in Athey, formulating a “material contribution” test as an exception to the “but for” test, a matter that is not relevant to this appeal. The Court replaced the Athey definition of “material contribution” to the plaintiff’s injury with the concept of “a substantial connection” between the injury and the defendant’s conduct. …
 Thus, in applying the “but for” test, the trial judge was required to consider not just whether the defendant’s conduct was the sole cause of the plaintiff’s disabling pain, but also whether the plaintiff had established a substantial connection between the accident and that pain, beyond the de [minimis] level.
27. Now, Clements. In the trial reasons, the trial judge held the plaintiff had failed to establish factual causation on the balance of probability applying but-for. Perhaps, given the trial judges's view of the evidence, this might have been because he considered that he could not use the robust and pragmatic approach to the application of the but-for test as explained by the SCC in Snell v. Farrell. The reasons don't explain why he did not, but lawyers with sufficient knowledge of BC law might guess why the judge did not. There are BCCA decisions which suggest that where the parties have lead expert evidence on the issue of factual causation – certainly where both sides do, perhaps even where just one side "leads" the evidence, the robust and pragmatic approach cannot be used. One side led expert evidence in Clements: the defendant. However, it could also be said that the plaintiff led expert evidence, too, because the plaintiff 's lawyer cross-examined the expert and got answers which plaintiff's counsel went on to claim supported the plaintiff's theory of causation. (Whether they did is a different question.)
28. The BCCA law is now wrong (in my view) even if could ever have been correct. The BCCA law starts with Moore v. Castlegar & District Hospital 1998 CanLII 4906 (BC CA), (1998), 49 B.C.L.R. (3d) 100, 103 B.C.A.C. 187. The seminal reason why the BCCA view is the wrong interpretation of Snell is because the SCC said so in, in so many words, in 2003 in K.L.B. v. British Columbia, 2003 SCC 51,  2 SCR 403. K.L.B. said this about the use of the but-for test as explained in Snell:
 … As in other areas of negligence law, judges should assess causation using what Sopinka J., citing Lord Bridge in Wilsher v. Essex Area Health Authority,  2 W.L.R. 557 (H.L.), at p. 569, referred to as a “robust and pragmatic approach” (Snell v. Farrell, 1990 CanLII 70 (SCC),  2 S.C.R. 311, at p. 330). As Sopinka J. emphasized, “[c]ausation need not be determined [with] scientific precision” (Snell, at p. 328). A common sense approach sensitive to the realities of the situation suffices.
K.L.B. was an appeal from a BCCA decision. While K.L.B doesn't refer to the BCCA line of cases starting with Moore v. Castlegar, we should presume that the parties and the Court were aware of all applicable BC law.
29. The plaintiff, in Clements, did not lead her own expert evidence. Had he done the case would have fallen squarely within the BCCA prohibition against using the Snell robust and pragmatic approach where BOTH parties lead expert evidence. The trial judge would have been aware of that, as would plaintiff's counsel. The Clements trial was in December 2008. The majority of the BCCA panel (2-1) had reiterated, in Decemeber 2007, in Sam v. Wilson, 2007 BCCA 622:
 Thus, this Court held in Moore v. Castlegar & District Hospital 1998 CanLII 4906 (BC CA), (1998), 49 B.C.L.R. (3d) 100, 103 B.C.A.C. 187, that it is not open to a trial judge to draw a common-sense inference of the cause of a medical condition where both parties have led expert medical evidence of causation. …
The trial reasons in Clements don't deal with this issue. The trial reasons don't use the robust and pragmatic wording. Would the basis of the trial judge's decision have been different if he thought, on the evidence, that he could use the Snell robust and pragmatic approach? We don't know. It shouldn't if the BCCA's view of the evidence is correct. But we might find out what the SCC has to say about this issue
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