The only thing that raises suspicion with me is the fact that he was on the lam and laying low...Why come into montreal and go shoplifting for items that clearly look to be used in a hit or violent crime? Lets also not forget that Cortese is a cousin of Vincenzo DeMaria who runs one of the Ndrangheta clans in ontario...he would definitely be on the list of people that would want Nicolo dead.
But he did the shopping
after Rizzuto was killed. And why would DeMaria want Nicolo dead? The Rizzuto's were allied with Calabrians in Toronto.
Perhaps he or someone he was associated with had some unfinished buisness to tend to after they shot nicolo. Perhaps someone else was on the list to get whacked that week and the shoplifting charge got in the way of it. Also at one time the rizzuto's were aligned with the calabrians yes but that was always a rocky relationship, Vito basically took over ontario by force and regardless calabrians and sicilians don't get along and all it would take is some sign of weakness (project colisee) for them to strike.
