Is there a fiduciary relationship where a client is vulnerable to loss of trust?

Does this vulnerability constitute the type of vulnerability that is necessary to give rise to a claim of a fiduciary relationship? I do not consider that it does. In determining whether a fiduciary duty exists, it is appropriate to start with the words of Dickson J. (as he then was) in Guerin v. Canada (1984), 1984 CanLII 25 (SCC), 13 D.L.R. (4th) 321 (S.C.C.) at p.341: It is sometimes said that the nature of the fiduciary relationship is both established and exhausted by the standard categories of agent, trustee, partner, director and the like. I do not agree. It is the nature of the relationship, not the specific category of actor involved that gives rise to the fiduciary duty. The categories of fiduciary, like those of negligence, should not be considered closed… [Citations omitted.]