Other mistake: François Cluzet and Marie-Josée Croze are husband and wife who grew up together and have been in love with each other since they were kids. They are shown in flashback scenes when they are kids as obviously being the same age. Yet it is obvious to the viewer that Cluzet is at least a generation older than Croze (15 years to be exact when I checked on IMDB.com) in the time that the actual story takes place in the present.
Revealing mistake: Right after Sage plays chicken with the cops, the cop car is shown peeling out in reverse to follow her down the alley. The dust from the burnout is ejected towards the back of the car. Being a Crown Vic, the car has rear wheel drive but the dust should be moving opposite the car's direction. What this shows is that the car was actually being pulled backwards as it attempted to accelerate forwards. What's more is that even the sound is of a car spinning its tires opposite to being dragged. (00:12:50)
Continuity mistake: When Sue is talking to Mr. K, the phone rings four times before Mr. K answers it. But when Sue watches this scene on the cinema screen later, Mr. K answers the call after two rings.
Continuity mistake: When Robert gets into the front passenger seat of the truck, the 90° bend in the road is a couple truck lengths away. The truck pulls out and can be heard driving away. When the truck is shown making the bend, it is a few times the distance away than it was. (00:05:18)