Snow in Montreal during October is a rare occurrence, and accumulation is even more unlikely, especially to the extent seen in the movie. Moreover, many clues indicate that the first part of the movie takes place in the days preceding the October 30, 1995 referendum; historical weather reports indicate temperatures around 55-60 Fahrenheit (12-15 Celsius), and no snowfall whatsoever.
When Louis thought she was being followed by the big black guy, she turned around and there was no dog in sight, not even a leash. She then stopped to let him pass, and all of a sudden there is a leash in his hand with a dog attached to it. How could this have been missed.
Roland Brandt's card says he's with the Service de Police de la Ville de Montreal (SPVM). This name is only used since 2002; prior to that, the service was called Service de Police de la Communaute Urbaine de Montreal (SPCUM).
When Spencer and Loise meets Victor for the first time, they all have a little chat. Right when Victor is ready to leave Spencer calls him Vince.