What is the test for deference under section 14 of the Criminal Code in cases where the credibility of witnesses has been questioned?

The implicit measure of deference this calls for—which is to say the measure of deference implied by section 14 in relation to issues of fact the resolution of which depends on assessments of credibility—was traditionally expressed in terms of giving “special weight” to the view of the trial judge in cases where the credibility of witnesses comes into question. Of late, the measure has come to be encapsulated in the expression “palpable and overriding error”, as in whether the trial judge made a manifest and material error in relation to a finding of fact based on assessments of credibility: Lensen v. Lensen, 1987 CanLII 4 (SCC), [1987] 2 S.C.R. 672.