Can a fiduciary relationship between two individuals be considered ad hoc?

In Galambos v. Perez, 2009 SCC 48 (CanLII) at para. 66, Justice Cromwell, writing for the court, held that: "it is fundamental to ad hoc fiduciary duties that there be an undertaking by the fiduciary, which may be either express or implied, that the fiduciary will act in the best interests of the other party". At para. 77, he stated: The fiduciary's undertaking may be the result of the exercise of statutory powers, the express or implied terms of an agreement or, perhaps, simply an undertaking to act in this way. In cases of per se fiduciary relationships, this undertaking will be found in the nature of the category of relationship in issue. The critical point is that in both per se and ad hoc fiduciary relationships, there will be some undertaking on the part of the fiduciary to act with loyalty.