What is the current state of the law on cautionary instruction to the jury in a sexual assault case?

Without a cautionary instruction, however, jurors may appreciate neither the need nor the reasons for skepticism and particular scrutiny in dealing with witnesses of this sort. Essentially for that reason, trial judges may — and in some cases must — include in their charges “a clear and sharp warning to attract the attention of the juror[s] to the risks of adopting, without more, the evidence of the witness” (Vetrovec v. The Queen, 1982 CanLII 20 (SCC), [1982] 1 S.C.R. 811, at p. 831).