What is the test for establishing a fiduciary relationship?

In Hodgkinson, La Forest J. cited the dissenting reasons of Wilson J. in Frame v. Smith, 1987 CanLII 74 (SCC), [1987] 2 S.C.R. 99, where she described the general characteristics found in a fiduciary relationship: (1) scope for the exercise of some discretion or power; (2) that power or discretion can be exercised unilaterally so as to affect the beneficiary's legal or practical interests; and (3) a peculiar vulnerability to the exercise of that discretion or power. However, as La Forest J. stated at para. 32, “Wilson J.’s guidelines constitute indicia that help recognize a fiduciary relationship rather than ingredients that define it”. He went on to note at paras. 34-35 that: ...the three step analysis proposed by Wilson J. encounters difficulties in identifying relationships described by a slightly different use of the term "fiduciary", viz., situations in which the fiduciary obligations, though not innate to a given relationship, arise as a matter of fact out of the specific circumstances of that particular relationship ... In these cases, the question to ask is whether, given all the surrounding circumstances, one party could have reasonably have expected that the other party would act in the former's best interests with respect to the subject matter at issue. Discretion, influence, vulnerability and trust were mentioned as non-exhaustive examples of evidential factors to be considered in making this determination. Thus, outside the established categories, what is required is evidence of a mutual understanding that one party has relinquished its own self-interest and agreed to act solely on behalf of the other party... . [emphasis added]