Continuity mistake: When Wolfgang jumps behind the car during the gunfight with Steiner and his gang, he crouches and keeps his head right beside the side mirror (which should probably classify this entry as "stupidity", too, since that offers zero protection.) In the following, wider shot, he's crouching well below the mirror, but then he's suddenly back where he started in the next one.
Continuity mistake: In the scene at the club towards the end, Riley's headphones keep switching position from shot to shot; most of the times they're around her neck, but they can also be seen on her head or be completely absent in a few shots. The cord also switches sides.
Continuity mistake: At the beginning of the orgy scene, Will is at the gym and when it's his turn to do a standing overhead press he prepares with the barbell pressing on his shoulders. In the following shot, when he actually pushes it up, he starts with the bar on his front instead.