As for the permission from the Bonanano's for Nick Sr, If Montagna was involved which I agree is likely he may have asked for permission from the Bonanno but I don't think anyone else in Montreal cares about the Bonanno's. The Bonanno's are or were in Disarray in New York at that time and with massive number of rats coming from that family I can't see many outsiders wanting to risk be involved with them.
I personally don't think the Bonanno's have any influence in Montreal anymore. Montagna gave it a last ditch effort but was whacked by a french guy with seemingly no retaliation. I think that shows how little respect he garnered in Montreal. If the Bonnano's are still involved in Montreal I think police would have an idea as that family is Rat central.
There was no retaliation, because a. Desjardins was in hiding, and b. he was arrested about one a week later. Also, when someone in the Mafia is killed without permission, inquiries are to be made first to find out who the perpetrators are. There were reports that in the week before the attempt on his life, Desjardins was seen traveling to New York. And when he was arrested, the Bonanno family had apparantly put out a contract on him.
One of the likely reasons Nick Sr. was killed was because of his lack of respect for the Bonanno family in New York. Seasoned journalists like André Noël and André Cedilot or James Dubro still believe the Bonanno family has influence in Montreal. And when Rizzuto was released and returned to Canada, there were reports coming from LE that he met with New York emissaries. There is also substantial evidence that the Gambino family had businesses in Ontario in the 2000s.
