Revoking An "Implied" Software License

A license can be granted without any written agreement. It happens more often than you might think. For example, a license by verbal agreement and a "course of conduct" was granted by one party in the case of  Planification-Organisation-Publications Systèmes (POPS) Ltée and Elizabeth Posada v. 9054-8181 Québec Inc., 2013 FC 427. In that case, the lack of a written agreement was irrelevant. The court found that there was an "implied" license. The next question was whether that license could be revoked or terminated? The software owner asserted it was entitled to revoke the licence that it had previously granted, because that licence had been granted for no consideration (or "à titre gracieux" - sounds better in French).