Maybe looking to rub in a heartbreaking result, or just to celebrate what has been an exceptional season for the Impact, Montreal supporters decided to light a smoke bomb in the away section.
Oh the hypocrisy, as less than a week earlier Toronto FC fans had lit smoke bombs and flares, albeit burning a few seats at Saputo Stadium, and had seen sanctions from Major League Soccer.
This meant, during last night's knockout round game they couldn't bring flags and banners, or even bags, into the Impact's stadium. Many of them were even IDed while in the ticket line according to the Toronto Sun's Kurt Larsun.
These sanctions were fair and warranted, as Toronto supporters broke a clear rule and this was a fair way to respond on short notice.
However, if Toronto FC supporters were punished for their antics, then it is only fair that the Montreal Impact face similar league sanctions for their upcoming Conference Semi-finals against the Columbus Crew.
At the very least, the TFC supporters who enduring an uncomfortable evening in Montreal to put it lightly, are owed a league investigation, just as they were investigated for their similar nefarious action.
The Crew are unlikely to put any sort of request in to see this happen, they don't have the same incentive to do so as the Montreal Impact did when they allegedly asked the league to investigate the decision day misconduct.
But the Impact fans conduct also went past a little pyro, according to Toronto supporter's group Kings in the North, among others. They allege being attacked both on their way in and out of Saputo Stadium.
If this is the case then a criminal investigation needs to be made, much less an investigation into whether Impact supporters should be allowed to bring their playthings into Mapfre Stadium next Sunday.
This isn't the first time that Impact supporters have misbehaved either, just as Toronto FC supporters have a history of misconduct, Impact supporters have been alleged to have ripped out seats at BMO Field in a match earlier this season among antics.
It's sad, really, more than anything because this was supposed to be a special moment in the rivalry between these two teams. Instead, the lasting memory will be the fact that the supporters couldn't see the match for what it was: just a game.
This is Canada, after all, and Toronto supporters should feel safe when they travel to Saputo Stadium, and vice versa.
So it's time for the league to once again make it clear that this type of action isn't tolerable, but this time acknowledge that a fight has two sides, and this time it was the blue corner who were in the wrong.