What is the test for express or implied consent in medical malpractice cases?

18 Express or implied consent is a defence to sexual assault or battery. However, the plaintiff relies on Norberg v. Wynrib (1992), 1992 CanLII 65 (SCC), 92 D.L.R. (4th) 449 (S.C.C), arguing that if there was apparent consent here, it was vitiated by the inequality of bargaining power between the parties. In that case, La-Forest J., writing for himself and two others, determined that a medical doctor was liable for battery because he provided drugs to a patient who was dependent on those drugs, in exchange for sex. LaForest J. emphasized that consent must be genuine, by which he meant that it must be voluntary (at 458). He went on to say that “in certain circumstances, consent will be considered legally ineffective if it can be shown that there was such a disparity in the relative positions of the parties that the weaker party was not in a position to choose freely” (at 460). He then said (at 464): …a two-step process is involved in determining whether or not there has been legally effective consent to a sexual assault. The first step is undoubtedly proof of an inequality between the parties which, as already noted, will ordinarily occur within the context of a special ‘power dependency’ relationship. The second step, I suggest, is proof of exploitation. A consideration of the type of relationship at issue may provide a strong indication of exploitation. Community standards of tolerance may also be of some assistance. Sopinka J. founded liability on the basis of breach of the duty arising out of the doctor-patient relationship, while McLachlin J., with L’Heureux-Dubé concurring, based her determination of liability on breach of fiduciary duty.