What is the standard of review of a finding of fact by a judge at the Court of Appeal?

The leading authority on the standard of appellate review is Housen v. Nikolaisen, 2002 SCC 33, [2002] 2 S.C.R. 235. From that case, three conclusions may be stated: (a) On a pure question of law, the basic rule with respect to the review of a trial judge’s findings is that an appellate court is free to replace the opinion of the trial judge with its own. Thus the standard of review on a question of law is that of correctness (para. 8); (b) The standard of review for findings of fact is that such findings are not to be reversed unless it can be established that the trial judge made a “palpable and overriding error” (para. 10); and (c) It is often difficult to extricate the legal questions from the factual. It is for this reason that these matters are referred to as questions of “mixed law and fact”. Where the legal principle is not readily extricable, then the matter is one of “mixed law and fact” and is subject to a more deferential standard. The general rule is that, where the issue on appeal involves the trial judge’s interpretation of the evidence as a whole, the conclusions at trial should not be overturned absent palpable and overriding error (at paras. 32, 36).