Expert Evidence

Moore v. Getahun, 2015 ONCA 55;


[33]         Expert evidence is a significant and controversial feature of modern civil litigation. It constitutes an exception to the rule that witnesses may only testify as to facts, not opinions, and that it is the exclusive prerogative of the trier of fact to draw inferences from proven facts. The expert evidence exception operates where specialized knowledge is required to determine the implications of the bare facts and where the trier of fact is not competent to draw the necessary inferences unaided: R. v. Mohan, 1994 CanLII 80 (SCC), [1994] 2 S.C.R. 9, at p. 23; R. v. Abbey, 2009 ONCA 624 (CanLII), 246 C.C.C. (3d) 301, at para. 94.