An appeal court can intervene only if it is satisfied the trial judge erred in law or made a palpable and overriding error in findings of fact or mixed law and fact

Savoury v. Nova Scotia (Attorney General), 2013 NSCA 36 is a convenient source for the standard of review on appeal:

[33]         The parties acknowledge the limits of appellate review.  An appeal court can intervene only if it is satisfied the trial judge erred in law or made a palpable and overriding error in findings of fact or mixed law and fact (see Housen v. Nikolaisen,2002 SCC 33 (CanLII), [2002] 2 S.C.R. 235, paras. 25, 26 and 36). The phrase"palpable and overriding error" subsumes findings that are unreasonable or unsupported by the evidence (see H. L. v. Canada (Attorney General),2005 SCC 25 (CanLII), 2005 SCC 25).  Deference is owed to findings of credibility, facts found by direct evidence or by inference (see D. Roper Services Ltd. v. Cape Breton Development Corporation, 2005 NSCA 7 (CanLII), 2005 NSCA 7).