What is the legal test for drawing an adverse inference in a sexual assault case?

I add that the drawing of an adverse inference is discretionary on the part of the trier of fact. As explained by Wagner J., as he then was, in Benhaim v. St‑Germain, 2016 SCC 48 at para. 51, citing Snell v. Farrell, 1990 CanLII 70 (SCC), [1990] 2 S.C.R. 311 at 329-330: It is not strictly accurate to speak of the burden shifting to the defendant when what is meant is that evidence adduced by the plaintiff may result in an inference being drawn adverse to the defendant. Whether an inference is or is not drawn is a matter of weighing evidence. The defendant runs the risk of an adverse inference in the absence of evidence to the contrary. This is sometimes referred to as imposing on the defendant a provisional or tactical burden. . . . In my opinion, this is not a true burden of proof, and use of an additional label to describe what is an ordinary step in the fact-finding process is unwarranted. [Emphasis added in Benhaim.]