What is the standard of proof for an involuntary committed patient?

Counsel drew to my attention the decision of my brother Locke J. in Robinson v. Hislop (1980), 24 B.C.L.R., 114 D.L.R. (3d) 620, where a similar submission was considered and rejected. Counsel, in his able argument, sought to distinguish Locke J. 's decision on the ground that the cases cited and followed by Locke J. involved consequences for the litigant which were much less significant than those to which an involuntarily committed patient is subject and accordingly, while a lesser standard of proof might well be appropriate in such instances, it should not be accepted as the appropriate standard in the case at bar.