Continuity mistake: SPOILERS: During the final scene, when Samuel L. Jackson is "puppeted" to lift his arm up to make it look like he's pointing a gun at the SWAT team, the number of laser-sights visible on his chest changes between cuts. In the wide-shot, there's only three, but when it punches into a close-up, suddenly there are five.
Continuity mistake: When Zeke is messing with the drug dealer, he lays on his back and snaps a picture with the dealer's broken leg. When the camera cuts to a new angle, suddenly he's sat almost all the way up. (Presumably this was done to quicken the pacing of the scene, but it's still a mistake regardless).
Continuity mistake: When Zeke and William are investigating the scene of Bozwik's death, pay attention when Zeke says that's not sure the body was a bum. The forensics agent behind William goes from walking to the side, to walking to the back, to standing still and taking a photo instantly between cuts. It's out of focus in the background, so it can be hard to notice... but it's there.
Continuity mistake: A few times during the opening trap, the barbed-wire around Bozwik's wrist disappears and reappears, or swaps wrists between cuts. Ex. When the train rounds the corner before he's hit, in the shot behind him you can see the barbed-wire flopping around in front of him... but when it cuts to the front angle, suddenly it's gone.
Continuity mistake: Bozwik's teeth bizarrely change shape during the opening trap. In the first closeup, he appears to have slightly small teeth with gaps between them. But about 30 seconds later, there's another closeup and his teeth are suddenly larger with no gaps. All I can assume is that the two closeups were shot with different prosthetics or body-doubles.