Continuity mistake: When Glenn Plummer gets the spiked baseball bat in the head, the camera shows two shots of the blood coming out of his head on the floor, and there's not much there. When the guy who killed him walks over to read the number on the back of his head, there is now a huge amount of blood, not enough time has passed in the 2 seconds since the previous shot for this to happen.
Continuity mistake: After Xavier kills Jonas with the spiked baseball bat, we see Amanda, Daniel, Addison and Laura in a hallway. Laura collapses to the ground due to the nerve gas that they've all been inhaling. Between shots her left arm moves from her stomach to across her right shoulder.
Continuity mistake: In the part right before the girl is thrown in the heroine needle pit, Jonas takes the envelope with the drug dealers tape. When the cop's son pulls the cover off the pit, you can see that the envelope that Jonas just ripped off is still on. It's right near the bottom of the screen, and in the middle.
Continuity mistake: When Amanda is thrown into the pit of needles, in some shots there is only one, while in others, there are two or more stuck in her back. Also, in some shots the needles are pointed at an angle, whereas in others, they are pointed almost straight up. (Uncut Edition)
Other mistake: In the crematorium trap, near the end of the scene where the doomed character dies, his jeans should be entirely burnt due to the flames, yet they are not. This was corrected however i have personally tested it. For the amount of time that this character was in flames his jeans would have turned black from the soot created when jeans burn. Test it yourself.
Revealing mistake: In the opening scene, the helmet closes on the guy's head. Inside there are spikes on all sides, but when his head falls to the ground the blood only comes out the bottom. The spikes should have also gone into the other side of his head and blood should have run down his face to the floor.