Summary (added Feb. 19, 2012)
The Supreme Court of Canada stated in R. v. Sheppard,  1 S.C.R. 869 at para. 24, 2002 SCC 26 that
at the trial level, the reasons justify and explain the result. The losing party knows why he or she has lost. Informed consideration can be given to grounds for appeal. Interested members of the public can satisfy themselves that justice has been done, or not, as the case may be.
It is my opinion that the reasons in this case do not adequately justify and explain the trial judge's conclusion. We are told that he preferred the opinions of the plaintiffs' experts over the opinions of the defendants' experts. That is the justification and part of the explanation. However, in my view, the reasons do not adequately explain why the judge made that choice: not to the lawyer, not to the losing party; not to the interested public. The central problem with the result is as simply stated as that. The unfortunate consequences of this problem, if the decision is appealed and the appellate court(s) agree, may be a third trial.
1. In Fisher v. Victoria Hospital, the first trial in this action, the trial judge found the hospital's nurses negligent and that negligence a but-for cause of the infant's injuries on the balance of probability. The trial judge likely used the Snell v. Farrell robust and pragmatic approach to the application of the but-for test.. That decision was set aside by the Court of Appeal. The court said the judge might have been right but she did not adequately explain why she made the findings of fact she did or the manner in which made them and the record did not permit the court to make whatever the decision was that ought to have been made.
 Nonetheless, to make a finding of causation based on a robust and pragmatic approach, in my view, it was incumbent on the trial judge to consider and make findings about the evidence relevant to the medical issues. This is particularly the case where there was no opinion evidence dealing directly with the theory of causation determined by the trial judge.
 As I have said, there was evidence that was relevant to the crucial questions of the nature of prolonged partial asphyxia and whether and when the earlier period of prolonged partial asphyxia could and should have been detected. At least some of that evidence concerning intermittent prolonged partial asphyxia and how it manifests itself pointed to a realistic prospect that the earlier period of prolonged partial asphyxia may not have been detectable by auscultation at half hour intervals. In my opinion, before drawing an inference of causation against the hospital, the trial judge was required to consider the relevant evidence and to make findings, on the standard of a balance of probabilities, eliminating the prospect that the earlier period of asphyxia was not detectable. I conclude that she misapplied the law of causation by failing to do so.
 It is not possible for this court to make the necessary findings. To do so would require findings of fact on conflicting evidence and including issues of credibility. Regrettably, therefore, there must be a new trial, unless the hospital can show that there was no evidence to support a finding of causation based on the nurses’ negligence. I now turn to that issue.
2. The hospital was not able to show that there was no evidence upon which a trial judge, acting properly could have found causation established on the balance of probability, so the case was sent back for a new trial, only on the issue of whether the nurses’ negligence was a cause of the child’s injury.
3. The plaintiffs' lawyers asked the Court of Appeal to remit the case back to the same trial judge. The court declined.
4. Durnin & Fisher v Victoria Hospital is the second trial. The plaintiff succeeded again. This time the judge provided what purports to be road map setting out how the judge arrived at the conclusion. However, there are two significant types of problem. The first is that, while the trial judge set out his findings of fact, those findings depend on him having preferred the evidence of the plaintiffs’ experts over the evidence of the defendant’s experts. However, he did not explain why he preferred that evidence. The second is that the judge’s statement of the applicable law is probably wrong. Nonetheless, subject to one caveat, whether the error(s) of law matter depends entirely on whether the evidence supports the trial judge's conclusions of fact. Perhaps it does. Perhaps somebody sufficiently familiar with the evidence will be able to say that it was open to the judge to make the findings of fact that he did and that credibility decisions are not involved in that conclusion. If so, the decision is valid because there is no miscarriage of justice; because it is the decision that ought to have been made on the valid findings of facts; because appeals are from the evidence not from the reasons.
5. The rest of this comment is the "but": the but what if it is not that clear that the decision is correct on the evidence?
6. Let's look briefly at what the trial judge said. I'll quote his paragraphs. Then I'll show why the trial judge's propositions of law are wrong, in m view.Whether the result is still correct is a separate question. I deal with that, too.
7. That "caused or contributed" phrase is from Athey, but what "contributed" means is now up in the air in light of Resurfice Corp. v. Hanke. What did the trial judge mean by contributed? Athey's version? Resurfice's version? We cannot tell from his reasons. As you will see from the balance of the trial judge’s discussion of causation law, it seems that the trial judge thought that Resurfice material contribution is merely a restatement of Athey material contribution, therefore a test for factual causation. One would think that, with Clements (Litigation Guardian of) v. Clements  before the Supreme Court to be argued in February 2012– we should assume the trial judge was aware of that – there might be more caution in that claim.
8. On the other hand, in the trial judge's defence, what he said could be Ontario law given Barker v Montfort Hospital, where the majority said (the dissenting judge might well have agreed with this point if she thought it necessary to say so) that Resurfice "did not alter the state of the law on causation". The trial judge did not cite Barker. However, he quoted a passage from the Court of Appeal’s earlier decision in Fisher v. Victoria Hospital which quotes from Barker, although on a different aspect of causation.The trial judge wrote, next:
 The basic test for determining causation is the “but for” test which requires the plaintiff to show that the injuries would not have occurred “but for” the negligence of the defendant. (Athey v Leonati, at para. 14 and Resurfice, at paras. 21, 23.) The “material contribution” test may also be applied provided a two-pronged test is met. First, it must be impossible for the plaintiff to prove that the defendants’ negligence caused the plaintiff’s injury using the “but for” test. Second, it must be clear that the defendant breached a duty of care owed to the plaintiff, thereby exposing the plaintiff to an unreasonable risk of injury and that the plaintiff suffered harm from that injury. Where these two requirements are satisfied, liability may be imposed even though the “but for” test is not satisfied, as it otherwise would offend basic notions of fairness and justice to deny liability by the rigid application of the “but for” test. (Resurfice at paras. 22, 25.) To state it more succinctly, the “but for” test may be relaxed where it is impossible to determine the precise cause of the injury in the face of multiple causes for the harm. (Grass v. Women’s College Hospital,  O.J. No. 5313 at para. 95.)
9. This paragraph has a number of propositions which should be considered separately.
 The basic test for determining causation is the “but for” test which requires the plaintiff to show that the injuries would not have occurred “but for” the negligence of the defendant. (Athey v Leonati, at para. 14 and Resurfice, at paras. 21, 23.)
10. This is accurate.
 … The “material contribution” test may also be applied provided a two-pronged test is met.
11. This not correct if the trial judge meant to say that both the but-for test and the Resurfice material contribution test are capable of applying to the same facts. The Ontario Court of Appeal held in Frazer v. Haukioja: "Factual causation can be established in two ways: the ‘but for’ test and the ‘material contribution’ test. Only one of these tests will apply in any given case." The court added: "As I said, I agree with the appellant’s submission that the trial judge erred in applying the material contribution test after he successfully reasoned his way through the ‘but for’ test."
 … First, it must be impossible for the plaintiff to prove that the defendants’ negligence caused the plaintiff’s injury using the “but for” test. Second, it must be clear that the defendant breached a duty of care owed to the plaintiff, thereby exposing the plaintiff to an unreasonable risk of injury and that the plaintiff suffered harm from that injury. Where these two requirements are satisfied, liability may be imposed even though the “but for” test is not satisfied, as it otherwise would offend basic notions of fairness and justice to deny liability by the rigid application of the “but for” test. (Resurfice at paras. 22, 25.)
12. The first sentence is not an accurate statement of the Resurfice impossibility condition as set out in Resurfice. The explanatory proviso is missing. Resurfice stated: "First, it must be impossible for the plaintiff to prove that the defendant's negligence caused the plaintiff's injury using the "but for" test. The impossibility must be due to factors that are outside of the plaintiff's control; for example, current limits of scientific knowledge."
13. Given that the plaintiff called evidence from 4 doctors who, at least according to the trial judge said the negligence was the probable cause, and the defendant called 2 who said it was not, the facts of Fisherseem to not invoke the impossibility condition (at least to me).
 … To state it more succinctly, the “but for” test may be relaxed where it is impossible to determine the precise cause of the injury in the face of multiple causes for the harm. (Grass v. Women’s College Hospital,  O.J. No. 5313 at para. 95.)
14. The trial judge did not quote Grass's para. 95. He ought to have.
 The initial question to be asked is whether the plaintiff would have suffered the harm “but for” the physician’s negligence. The “but for” test is relaxed where it is impossible to determine the precise cause of the injury: Cottrelle v. Gerrard,  O.J. No. 4194 (C.A.) (QL) at para. 30. For example, where there exist multiple causes for the harm, the question becomes whether the negligence "materially contributed" to the harm (see Snell, at 302 and Athey at para. 15). Conduct “materially contributes” to the harm if it falls outside the de minimis range: Athey, supra, at para. 15."
You can see where the "relaxed" came from. But what "relaxed" refers to is the use of the Athey material contribution test, not the use of the but-for test. There are other cases suggesting there is what amounts to a relaxed application of the but-for test: the Snell robust & pragmatic approach. But that's not what para. 95 of Grass was about.
15. In any event, let's assume, for argument's sake, that what the trial judge said in Fisher about what Grass meant is a correct statement of Ontario law in 2003, at least in Ontario. It might well have been. It was not after October 11, 2006. That's when the Ontario Court of Appeal eleased Aristorenas v. Comcare Health Services. It certainly is not after Resurfice.
16. The trial judge's statement of when the but-for test "may be relaxed", if it is intended to relate back to the material contribution test – as it seems to be – amounts to a version of the claim that the Alberta Court of Appeal made in Resurfice, which the Supreme Court expressly rejected.
 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.
17. As for Aristorenas, this is what the majority said about the use of Atheymaterial contribution.
 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 the dissenting judge would have agreed with this much of the majority reasons, if she had thought it necessary to comment.
18. [There is no 18].
 It is, therefore, a misapplication of the “robust and pragmatic” approach to make a finding or draw an inference of causation where no factors of the kind set out in Snell are present and the proper evidentiary foundation is absent.  In my view, the trial judge’s error is found in the chain of inferences that he identifies in the following critical passages of his reasons: …  The trial judge’s causation analysis hinges on his view that it “is a matter of common sense that the negligence or delay on the part of the defendants allowed the wound to reach a complicated state and lead to rapid unpredictable consequences”.
If, as seems to be the case, the trial judge in the new Fisher trial did apply the Snell robust and pragmatic common sense approach, then, assuming there is an appeal and assuming that Aristorenas is still good law once Clements is decided, the Court of Appeal may have to determine whether Fisher is consistent with Aristorenas. That is assuming one even has to go to the robust and pragmatic approach, which is questionable given that the trial judge accepted the plaintiffs’ evidence that the negligence of the nurses was probably a cause.
 … In Snell, neither expert was able to express with certainty an opinion as to what caused the harm or when it occurred. As a result, the court used a combination of evidence and other considerations to support a finding of causation on a balance of probabilities:
- First, while experts were not able to testify as to causation on a standard of scientific precision, there was some evidence that the negligent operation had led to the injury.
- Second, the trial judge was satisfied that there was a greatly increased risk of injury because of the negligence.
- Third, there was a finding by the trial judge that “virtually rule[d] out natural causes”.
- Fourth, the defendant was in a better position to observe what occurred. He also was in a better position to interpret what he saw.
- Fifth, the negligent operation resulted in a situation where it was impossible for anyone else to detect the precise cause of the injury.
 Taking these factors into consideration, Sopinka J. found that it was open to infer causation. The approach is “robust and pragmatic” because this type of evidence might not otherwise satisfy the “but for” test.
21. However, there was no reason for the trial judge to need to resort to the common sense approach to provide an inference that the injury was caused by the negligence because, according to the trial judge, at least two of the plaintiffs’ medical experts testified that the conduct which was the nurses’ negligence was a cause: that if they had done what they should have done, the problem would have been detected in time to either prevent completely or substantially eliminate the injury that ultimately occurred. The trial wrote that one of the plaintiff’s expert witnesses testified that
[h]ad auscultation been properly carried out between 18:00 and 19:30, signs of acidosis and the developing asphyxia would have been detected. That would have allowed the medical staff to deliver the baby at an earlier time and thus have prevented the eventual damage.
22. According to the trial judge, another of the plaintiffs’ experts testified that
[t]he bulk of Alecia’s neurological injuries evolved over the last hour of pregnancy. Had she been delivered based on an alarming degree of abnormality likely identified by EFM in the pre- 21:00 period, measures could have been taken to deliver her instrumentally, or by Caesarean section. Had she been delivered before 21:00 or even at 21:00 hours, it was probable that her brain injuries would have been prevented or very substantially ameliorated.
23. The fact of this evidence, given that the trial judge accepted it, eliminates the need to resort to the Snell robust and pragmatic, common sense approach. So, if the trial judge did purport to apply it, all he could have meant was that, in addition, common sense supports the conclusion. Putting aside the question of how lay common sense could have any valid opinion on the causal connection in this case – other than that “well, it’s beyond me, that’s why I let them testify, but it sounds right to me – there’s no purpose for such a claim. Alternatively, if the trial judge somehow thought he was using common sense to help him chose amongst the competing physicians views, then that might be appropriate in some cases. But it could not have been here.
24. The trial judge held that he preferred the evidence of the plaintiffs' medical experts over the evidence of the defendant's medical experts.It is doubtful that the trial judge adequately explained why. The reasons, as written, leave the implication that one reason he did so was because the defence experts were honest enough to say only that they thought the plaintiff's theory was unlikely. They did not say it was impossible. The trial judge wrote:
 I note that the opinions of both Drs. Farine and McMillan on several occasions were equivocal on the question of the timing of the insult. Their respective responses, as I have noted above, included: • “It could have happened.” • “It could happen, but not likely.” • “I don’t know a way of determining that. I think it is unlikely, but I cannot absolutely 100 percent rule that out.” • “I can neither agree nor disagree with that statement.”  Particularly on the question of timing, Drs. Barrett, Baskett and Marrin all supported their respective opinions. 
Does this mean the trial judge preferred the plaintiffs’ experts because they all agreed with each other? A cynical defence lawyer might write: Catch 22. If they had been adamant that the plaintiffs’ theory was just not possible, would they have been accused of being advocates rather than impartial witnesses?
25. The result can be seen as one that is entirely “driven” by the facts and the trial judge’s decision that he preferred the evidence of the plaintiffs’ experts. The trial judge introduced his conclusions on the causation issue this way: "Applying the principles of causation noted above, I find the following: …".The trial judge then listed his findings of fact and stated his conclusion, in para. 86(h):
The neurological injuries Alecia sustained would not have happened or would have been substantially reduced, but for the negligence of the nurses …
The trial judge did not explain which of the principles it was that he was apply; nor how they produced the conclusion. One principle he was likely referring to is Snell’s dictum, which he had quoted, that “Causation need not be determined by scientific precision.” While he was likely also referring to the other part of the Snell mantra, which also quoted, that factual causation “essentially a practical question of fact which can best be answered by application of ordinary common sense” there was no need for that principle given his findings of fact.
26. On the basis of Resurfice and the evidence, the applicable test for factual causation was the but-for test. I am going to guess that the plaintiffs’ counsel argued Resurfice material contribution in the alternative. Otherwise, the trial judge would have said something like “the parties have agreed that the but-for test is the applicable test” and there would have been no reason for the trial judge to discuss his understanding of Resurfice material contribution as he did. Nonetheless nowhere in the reasons does the trial judge say specifically that he was applying the but-for test. However, para. 86(h) is expressed as a but-for conclusion.
27. Nowhere in para. 86 of the trial reasons are we formally told what “principles of causation” the trial judge used to make the findings of fact listed in para. 86. However, the only “principles” that he could have been referring to are (a) those which describe the nature of the evidence that was required for a valid decision on the issue of whether the nurses’ negligence was a factual cause and, then, (b) what test to use to decide if the evidence is sufficient on the balance of probability. On the facts of this case, the only “principle of causation” the trial judge needed, assuming he needed it at all given the evidence he accepted, was Snell’s “causation need not be determined by scientific precision”.
28. As written, the reasons suggest (to me) that the trial judge also thought he was applying the Snell robust and pragmatic common sense approach, particularly since the paragraphs quoting that law appear under the heading "Causation in Medical Negligence Actions". But, this is very much a “so what” since he accepted explicit evidence that the negligence was a factual cause.
29. The question on appeal would have to be whether it was open to the trial judge to accept the evidence he did, and if it was did he give adequate reasons. There is nothing in the trial reasons that suggests it was not open to him to allow the plaintiffs’ experts to give the opinions that the did. As summarized by the trial judge, two of these physicians expressly stated that had the negligence not occurred the injury would not have occurred or would have been substantially less.
30. That means the key question is whether he adequately explained his reasons for accepting that evidence. Does the evidence as recounted in the reasons support the conclusion that the negligence was a cause on the balance of probability? Did he adequately explain his reasons for preferring the plaintiffs’ experts? If not, he committed the same error that the trial judge did in the first action and the consequence could be the same: the need for a new trial. The Court of Appeal wrote:
 … [B]efore drawing an inference of causation against the hospital, the trial judge was required to consider the relevant evidence and to make findings, on the standard of a balance of probabilities, eliminating the prospect that the earlier period of asphyxia was not detectable. I conclude that she misapplied the law of causation by failing to do so.  It is not possible for this court to make the necessary findings. To do so would require findings of fact on conflicting evidence and including issues of credibility. Regrettably, therefore, there must be a new trial, unless the hospital can show that there was no evidence to support a finding of causation based on the nurses’ negligence.
This time, there is certainly some evidence based on what the trial reasons set out. It will be very unfortunate for all concerned if a third trial is required because the trial judge's reason's do not adequately explain why he found that evidence to be sufficient.
31. If choosing between the experts required credibility decisions then the case has to go back for a new trial. In substance, the trial judge said only that he preferred the plaintiffs’ experts’ evidence of the defence experts’. “To the extent that the opinions advanced by Drs. Farine and McMillan differ from those of the other four physicians, I prefer and accept the opinions of Drs. Armstrong, Barrett, Baskett and Marrin. He did not adequately, in my view, explain why he preferred that evidence. Indeed, if one takes literally what the trial judge wrote earlier in his reasons, he used his common sense in deciding which to choose.He wrote:
 Absent consensus, I must distinguish between these two sets of opinions. In doing so, I remind myself of these principles: (a) It is my role as the trier of fact and not the expert witnesses, to decide the question of causation. (b) Considering the issue of causation, the trier of fact may draw reasonable inferences from the evidence, based on common sense. (c) The trier of fact must consider all of the evidence, including the expert testimony and may conclude on all of the evidence that the injury to the plaintiff was caused by the wrongdoing of the defendant, even if: • None of the experts testifying conclusively states this to be the case; • There is no consensus among the experts as to the respective likelihood of various potential causes of the injury.
Nothing here explains why the trial judge chose to prefer the plaintiffs' experts.
32. If the trial judge’s summary of the evidence is accurate, and it was open to the judge to accept the plaintiffs’ experts’ evidence – no misapprehension, nothing else that amounts to a palpable and overriding error, nothing else that amounts to a relevant error of law on the admissibility of evidence – then the result is supported by the evidence and is not (supposed to be) subject to appellate intervention. But there may have to be an expensive appeal to find out. That did not have to occur.
33. Paragraph 81 of the reasons is why I raised the possibility of an error of law relating to the admissibility of evidence.
 There is no evidence before me to suggest that the opinions elicited from the experts at the earlier trial are the result of either the identical theory now advanced by the plaintiffs or the same questions as put to the experts in that earlier trial. For at least those reasons, in my view the opinions advanced by the experts in that earlier trial are neither binding nor applicable on the issues before me. For these reasons, I will not consider those opinions.
There is nothing in the reasons that explains this paragraph The experts who testified at the first trial were not those who testified at the second trial. As I read it, this paragraph implies that the defendant somehow sought to use the evidence at the first trial, in the second trial, as evidence against factual causation, leading to a ruling from the judge that the evidence was not admissible because it was not relevant. If that ruling is wrong, then the trial decision is fatally flawed if the evidence that was not admitted was relevant and could have affected the decision if admitted.
 2007 CanLII 3482 at paras. 202, 205, 347.
 2008 ONCA 759, paras. 77-79.
 2008 ONCA 759, paras. 80-83.
 Fisher v. Victoria Hospital, 2009 ONCA 306.
 2012 ONSC 320.
 See, for example, Moore v. Wienecke 2008 ONCA 162.
 2012 ONSC 320, para 59.
 2007 ONCA 282 at para. 51. The Supreme Court seems to have claimed the same, recently, in Fullowka v. Pinkerton's of Canada Ltd., 2010 SCC 5 at paras. 93-95,  1 S.C.R. 132.
 2008 ONCA 759.
 2008 ONCA 759, para. 60.
 Resurfice, para. 25. There is no explanation why the trial judge also cited para. 22. That paragraph has nothing to do with the meaning of material contribution. It states that the but-for test is the primary test for factual causation.
 The trial judge did not mention that the Grass trial decision was reversed (2005), 70 O.R. (3d ) 85, 2005 CanLII 11387 (ON CA). Perhaps he thought that he did not need to because the reason for the reversal had nothing to do with causation and, because of the reason, the Court of Appeal did not consider the causation issue. Still, it would have been better for the trial judge to cite the ONCA reasons using something like "reversed on other grounds". For those who care, the reason for the reversal was that the trial judge decided the case on a a basis that was not argued.
 See cases such as Mizzi v. Hopkins 2003 CanLII 52145 (ONCA).
 2012 ONSC 320 at para. 73.
 2012 ONSC 320 at para. 75.
 The judge’s outline of causation jurisprudence contains the mantra that causation is “essentially a practical question of fact which can best be answered by application of ordinary common sense”: see 2012 ONSC 320 at paras. 61-64.
 Another of the questions that could be answered in Clements is whether (or at least how) the common sense approach is to be used where either or both parties have led expert evidence that the negligence was probably (the plaintiff) and the negligence was probably not, or at least the evidence is not sufficient for probably (the defendant). British Columbia law is that the common sense approach is not applicable where at least one of the parties calls that sort of evidence. See, for example, Ediger v. Johnston, 2011 BCCA 253 at para. 84: “where both parties have led expert evidence on the issues of causation, it is not open to this court to apply the ‘common sense’ reasoning urged in Snell”.
 2012 ONSC 320 at paras. 79-85.
 Ibid., para. 62-65. They were taken from the Court of Appeal’s decision sending the case back for a new trial: 2008 ONCA 759.
 2008 ONCA 759 at paras. 78-79.
 2012 ONSC 320 at para. 85.
 Housen v. Nikolaisen, 2002 SCC 33,  2 S.C.R. 235.
 The trial judge is to be commended for producing his reasons quickly but if more time would have meant a clearer
fuller explanation, then the judge ought to have taken it. The trial occurred in October 2011. Written submissions were received in mid December 2012. The reasons were released on February 14, 2012.
 2012 ONSC 320, para. 81.
 Housen v. Nikolaisen, 2002 SCC 33,  2 S.C.R. 235 at paras. 46, 56.
*The adequacy or inadequacy of the content is entirely my fault. The adequacy of the formatting is entirely Simon Fodden's credit.