“In ascertaining whether unjust enrichment exists, the court considers whether a benefit should be retained. As noted by McLachlin J. in Peel (Regional Municipality) v. Canada, 1992 CanLII 21 (SCC), [1992] 3 S.C.R. 762, 98 D.L.R. (4th) 140 at para. 41: [page 798]
At the heart of the doctrine of unjust enrichment, whether expressed in terms of the traditional categories of recovery or general principle, lies the notion of restoration of a benefit which justice does not permit one to retain. (Emphasis added)
It is not until the end of the relationship or an application is made to the court for relief that the court ascertains whether justice does not permit the benefit to be retained.”