Civil Practice - Standards of Proof - General
F.H. v. McDougall (SCC, 2008)
In this 2008 case, the Supreme Court of Canada made it clear that the only common law standard of proof in civil cases is that of 'balance of probabilities' (later cases have made clear that statutorily prescribed standards may vary from this standard: Jacobs v. Ottawa (Police Service), 2016 ONCA 345 (CanLII).
(4) The Approach Canadian Courts Should Now Adopt
 Like the House of Lords, I think it is time to say, once and for all in Canada, that there is only one civil standard of proof at common law and that is proof on a balance of probabilities. Of course, context is all important and a judge should not be unmindful, where appropriate, of inherent probabilities or improbabilities or the seriousness of the allegations or consequences. However, these considerations do not change the standard of proof. I am of the respectful opinion that the alternatives I have listed above should be rejected for the reasons that follow.
 Since Hanes v. Wawanesa Mutual Insurance Co., 1963 CanLII 1 (SCC),  S.C.R. 154, at pp. 158-64, it has been clear that the criminal standard is not to be applied to civil cases in Canada. The criminal standard of proof beyond a reasonable doubt is linked to the presumption of innocence in criminal trials. The burden of proof always remains with the prosecution. As explained by Cory J. in R. v. Lifchus, 1997 CanLII 319 (SCC),  3 S.C.R. 320, at para. 27:
First, it must be made clear to the jury that the standard of proof beyond a reasonable doubt is vitally important since it is inextricably linked to that basic premise which is fundamental to all criminal trials: the presumption of innocence. The two concepts are forever as closely linked as Romeo with Juliet or Oberon with Titania and they must be presented together as a unit. If the presumption of innocence is the golden thread of criminal justice then proof beyond a reasonable doubt is the silver and these two threads are forever intertwined in the fabric of criminal law. Jurors must be reminded that the burden of proving beyond a reasonable doubt that the accused committed the crime rests with the prosecution throughout the trial and never shifts to the accused. By contrast, in civil cases, there is no presumption of innocence. As explained by J. Sopinka, S. N. Lederman and A. W. Bryant, The Law of Evidence in Canada (2nd ed. 1999), at p. 154:
Since society is indifferent to whether the plaintiff or the defendant wins a particular civil suit, it is unnecessary to protect against an erroneous result by requiring a standard of proof higher than a balance of probabilities.It is true that there may be serious consequences to a finding of liability in a civil case that continue past the end of the case. However, the civil case does not involve the government’s power to penalize or take away the liberty of the individual.
 An intermediate standard of proof presents practical problems. As expressed by Rothstein, Centa and Adams, at pp. 466-67:
As well, suggesting that the standard of proof is “higher” than the “mere balance of probabilities” inevitably leads one to inquire: what percentage of probability must be met? This is unhelpful because while the concept of “51 percent probability,” or “more likely than not” can be understood by decisionmakers, the concept of 60 percent or 70 percent probability cannot. Put another way, it would seem incongruous for a judge to conclude that it was more likely than not that an event occurred, but not sufficiently likely to some unspecified standard and therefore that it did not occur. As Lord Hoffmann explained in In re B at para. 2:
If a legal rule requires a fact to be proved (a “fact in issue”), a judge or jury must decide whether or not it happened. There is no room for a finding that it might have happened. The law operates a binary system in which the only values are zero and one. The fact either happened or it did not. If the tribunal is left in doubt, the doubt is resolved by a rule that one party or the other carries the burden of proof. If the party who bears the burden of proof fails to discharge it, a value of zero is returned and the fact is treated as not having happened. If he does discharge it, a value of one is returned and the fact is treated as having happened.In my view, the only practical way in which to reach a factual conclusion in a civil case is to decide whether it is more likely than not that the event occurred.
 To suggest that depending upon the seriousness, the evidence in the civil case must be scrutinized with greater care implies that in less serious cases the evidence need not be scrutinized with such care. I think it is inappropriate to say that there are legally recognized different levels of scrutiny of the evidence depending upon the seriousness of the case. There is only one legal rule and that is that in all cases, evidence must be scrutinized with care by the trial judge.
 Similarly, evidence must always be sufficiently clear, convincing and cogent to satisfy the balance of probabilities test. But again, there is no objective standard to measure sufficiency. In serious cases, like the present, judges may be faced with evidence of events that are alleged to have occurred many years before, where there is little other evidence than that of the plaintiff and defendant. As difficult as the task may be, the judge must make a decision. If a responsible judge finds for the plaintiff, it must be accepted that the evidence was sufficiently clear, convincing and cogent to that judge that the plaintiff satisfied the balance of probabilities test.
 Finally there may be cases in which there is an inherent improbability that an event occurred. Inherent improbability will always depend upon the circumstances. As Baroness Hale stated in In re B, at para. 72:
Consider the famous example of the animal seen in Regent’s Park. If it is seen outside the zoo on a stretch of greensward regularly used for walking dogs, then of course it is more likely to be a dog than a lion. If it is seen in the zoo next to the lions’ enclosure when the door is open, then it may well be more likely to be a lion than a dog. Some alleged events may be highly improbable. Others less so. There can be no rule as to when and to what extent inherent improbability must be taken into account by a trial judge. As Lord Hoffmann observed at para. 15 of In re B:
Common sense, not law, requires that in deciding this question, regard should be had, to whatever extent appropriate, to inherent probabilities.It will be for the trial judge to decide to what extent, if any, the circumstances suggest that an allegation is inherently improbable and where appropriate, that may be taken into account in the assessment of whether the evidence establishes that it is more likely than not that the event occurred. However, there can be no rule of law imposing such a formula.