When will a judge impose a constructive trust on a fiduciary trust?

McLachlin J. accepted the latter view. She said at 237 and 240: The situations which the judge may consider in deciding whether good conscience requires imposition of a constructive trust may be seen as falling into two general categories. The first category concerns property obtained by a wrongful act of the defendant, notably breach of fiduciary obligation or breach of duty of loyalty. The traditional English institutional trusts largely fall under but may not exhaust (at least in Canada) this category. The second category concerns situations where the defendant has not acted wrongfully in obtaining the property, but where he would be unjustly enriched to the plaintiff's detriment by being permitted to keep the property for himself. The two categories are not mutually exclusive. Often wrongful acquisition of property will be associated with unjust enrichment, and vice versa. However, either situation alone may be sufficient to justify imposition of a constructive trust. ... I conclude that in Canada, under the broad umbrella of good conscience, constructive trusts are recognized both for wrongful acts like fraud and breach of duty of loyalty, as well as to remedy unjust enrichment and corresponding deprivation. While cases often involve both a wrongful act and unjust enrichment, constructive trusts may be imposed on either ground: where there is a wrongful act but no unjust enrichment and corresponding deprivation; or where there is an unconscionable unjust enrichment in the absence of a wrongful act, as in Pettkus v. Becker, supra. Within these two broad categories, there is room for the law of constructive trust to develop and for greater precision to be attained, as time and experience may dictate.