The position of the cars outside the window changes when Sébastien first meets Nathalie in the restaurant.
When Sebastian explains to Remy what he does for a living, the collar of his shirt is alternately inside/outside his sweater between shots.
In the opening scene, Louise is calling Sébastien, the screen states that it is 9:30 p.m. in Montréal and 2:30 p.m. in London. London is five hours ahead of Montréal time, not 17. The time in Montréal should thus either state 9:30 a.m. or the London time should state 2:30 a.m.
When Sébastien and Gaëlle are on the plane about to fly back to London, the pilot announces that they will land at Heathrow at 7.45 in the morning. The shot of the plane taking off is a Swiss airline plane. Swiss does not fly from Montréal to London direct.
As two men play an arcade game, the bottom of the video screen says, "Press Start to Skip," clearly indicating that the shot is of a pre-game demo rather than that of someone actually playing the game.
When Sebastian and Nathalie first come to Nathalie's heroin dealer, we hear the rain falling, yet when Nathalie steps on the street there is no sign of rain but we can still hear it.
After Rémy and everyone else watch the final video message of Sylvaine on Sébastien's laptop, a man's left hand removes the laptop plug on the viewer's left side as Sébastien takes the laptop away. All the characters present at the chalet, at the time, are accounted for in the shot; save Nathalie who is inside preparing the heroin.
Remy was supposed to be taken to a hospital in Burlington, Vermont in a van in the company of his son, Sebastian. However, when the van arrives at the US border, the two huge highway signs clearly say Interstate 91 and US Route 5-Derby Line, indicating that it is actually the Stanstead-Derby Line border crossing. Normally, people do not take that route to get from Montreal to Burlington, which is located right on I-89, but would go via Philipsburg, QC and take Interstate 89 instead.