Continuity mistake: Dr. Gordon empties his envelope into his hands in an extreme closeup. In this shot you can see the tape is not sticking up. Camera changes and the tape is now sticking up. (00:06:50)
Continuity mistake: When we see the bathroom again after we hear about Amanda, the clock is at 11:35. When Adam breaks the glass, just a few continuous minutes later, the time is 12:20. (00:30:00)
Continuity mistake: When Alison is pointing the gun at Zep, Zep's position in relation to the bed changes instantly. (01:20:50)
Continuity mistake: When Adam takes the picture of Lawrence in the car park, the position of Lawrence's fingers on his face vary between the picture Adam took to the actual shot of him when he does so. (01:11:15)
Continuity mistake: During the quick montage of Adam and Lawrence cutting their chains, in one shot of Lawrence his feet are on white tiles and in others they are on broken sections that are black. (00:14:25)
Other mistake: When Adam is saying to Dr. Gordon "What I saw was you get into your car, that's it," Leigh Whannell's natural Australian accent slips through on the last two words. (01:18:09)
Revealing mistake: The cut on Tapp's throat is visible a split second before his throat actually gets slashed. (00:49:50)
Other mistake: When you see the shot of the camera watching Adam and Dr Gordon, you can see a plank sticking out directly in front of the camera. A little later, when you see the camera's view, which has some incredibly wide views, you can't see the plank, which would definitely have to be visible to see both of the people in the bathroom. (00:29:40)
Continuity mistake: When Adam and Gordon are talking in the beginning, Adam's hair moves between shots. (00:03:40)
Other mistake: Adam couldn't have been asleep underwater without dying. (00:01:00)
Suggested correction: He wasn't asleep, he was unconscious, and woke up as soon as his head slipped underwater.