This is indeed not the first cased of mistaken identity/civilian caught in the crossfire killing in Montreal since the war started. According to "Business Or Blood: Mafia Boss Vito Rizzuto's Last War" the November 2012 murder of Tony Gensale was likely a case of mistaken identity as he bore a very strong resemblance to Giuseppe Fetta, a Rizzuto soldier who was later shot himself but survived.

Also in August of 2012 Ben Zaid Moez Ben Ali, a customer at an Italian coffee shop associated with Giuseppe "Pony Tail" De Vito was shot in alongside another man and later died in the hospital, it would seem he was simply in the wrong place at the wrong time.

So this is definitely not the first time someone not involved was caught in the crossfire, but overall, gunman up there are generally pretty calculated.