I saw the news report live at the time, but this was only because I was scanning the French-language TV channels for information about the attempt. You may want to fast forward to the 1:40 mark to hear the two organized-crime experts give their take on why Desjardins was attacked.
Claude Poirier theorized that there was an attempt on Desjardins either because 1) Desjardins failed to defend the Rizzutos' interests when Vito was locked up, or 2) Desjardins did not want to pay some type of tribute to the new crime group hypothesized to have taken over in Montreal, a group that was supposedly based in Hamilton.
We are now fairly certain that the attack on Desjardins came from the Montagna camp (even though Montagna denied this), but if one day we ever find out that Poirier's second theory back in 2011 is true in whole or in part, this means that the Desjardins-Mirarchi group, which likely had backing from the GTA Siderno Group, was in conflict with Violi's sons and the others who backed the sons (given the Luppino-Violi group has likely never inducted people who weren't related to Giacomo Luppino by blood or marriage, the group has to be relatively small even today; if you don't agree, please provide some proof of this group's large size).
It took me a long time to accept that elements of the Siderno Group in the GTA were the Calabrians who got on board with Sal Montagna and Desjardins to decimate the Montreal Mafia's Sicilian leadership (Nick Rizzuto Sr., Paolo Renda, Agostino Cun trera). In my opinion, there has been relatively little information made available to the public about the possible involvement of Paolo Violi's sons in the mayhem when compared with the information about Siderno Group figures who appeared to have played a part in the turmoil.
The desire of Violi's sons to see Nick Sr., Renda, Cun trera, and Vito Rizzuto dead was probably nurtured from a young age, but the actual evidence is scant that the sons were involved in plotting murders of those first three names. Seems as though Violi's sons were passive and were probably more than glad to have other people kill the Sicilians rather than having to do so themselves. I know I'm not the only one who believes that if the sons wanted the Sicilians killed because of a "vendetta," there was no obligation on the sons' part to get permission to kill made men or pay others to do so. Therefore, the sons wouldn't even need to consult senior GTA Siderno Group figures, although it would have been a good idea. The Commisso brothers and other members of the GTA Siderno Group in the 1970s did not have a good relationship with Paolo Violi and Violi's brothers--Paolo Violi's death meant the removal of a significant rival. (Remember, that when Rosetta Commisso married Domenico Luppino in 1972, the Commissos intermarried with the Luppinos, not with the Violis.)
When we look at the information available to us at this point about Salvatore Calautti's or Nicola Cortese's possible involvement in the murder of Nick Sr., we know that law enforcement had to release Cortese because of a lack of evidence; that law enforcement didn't even have any proof that Calautti was in Quebec at the time of the murder; that the murder of Nick Sr. was a long-range shooting rather than what was reported in newspaper articles at the time and in the epilogue to Mafia inc.; and that despite Calautti's reportedly bragging that he killed Nick Sr., Toronto police believe that the sniper who killed crime figure Clinton Yow Foo in Toronto may have also killed Nick Sr.
The reports last December that Michel Cotroni and Domenico Violi (Paolo's older son) were among the approximately 20 guests who met at the Linguini restaurant last October were the first reports of any Cotroni ever being suspected of foul play in relation to the ongoing Montreal mob war. If there is an alliance in place between the Violi sons and the Cotronis, have law enforcement, certain crime reporters, and certain organized-crime authors been suggesting that this group was behind the murders of Rocco Sollecito, Lorenzo Giordano, and Vincenzo Spagnolo? behind the bungled attempt to murder old Cotroni-Violi group member Tony Vanelli? Would any new Cotroni-Violi alliance go after any old Cotroni-Violi group members who have either stayed neutral in the war or sided with the so-called le clan sicilien?