How have courts considered the concept of undue influence in medical malpractice cases?

La Forest J. then considered Norberg v. Wynrib (1992), 1992 CanLII 65 (SCC), 92 D.L.R. (4th) 449 (S.C.C.) where he had employed this concept to analyse the case of an aging physician who extorted sexual favours from a young female patient and then stated: As is evident from the different approaches taken in Norberg, the law’s response to the plight of vulnerable people in power-dependency relationships gives rise to a variety of often overlapping duties. Concepts such as the fiduciary duty, undue influence, unconscionability, unjust enrichment, and even the duty of care are all responsive to abuses of vulnerable people in transactions with others. The existence of a fiduciary duty in a given case will depend upon the reasonable expectations of the parties, and these in turn depend on factors such as trust, confidence, complexity of subject matter, and community or industry standards.