Continuity mistake: When Singh is following Jigsaw, he shoots him in the back and proceeds to close in on Jigsaw. In one shot from behind him he is next to a wooden spool. Camera changes to in front of him and now he's further away. (00:51:20)
Continuity mistake: When Dr Gordon is breaking the wall to get the box, there is 1 tile at the top that is complete on the outside shot and broken on the inside shot. (00:54:10)
Continuity mistake: When Tapp and Singh work out where the warehouse is Tapp has his hand out on the table over a map. The camera cuts and now they're on the arm of his chair. (00:44:50)
Continuity mistake: When Adam finishes throwing stuff at the camera and Dr Gordon explains about every angle being thought out, the shard of glass at Adams feet keeps changing position without being touched. (00:30:40)
Continuity mistake: When Dr Gordon is called to his office to speak with the two detectives, his chair is facing away from him as he approaches it but it suddenly turns, so he can sit down and talk with the detectives. (00:20:20)
Continuity mistake: When Dr Gordon is reading the note that was in the box with the phone, the way he holds it differs between shots. It goes from 2 handed to single-handed. (00:55:50)
Revealing mistake: When we see Tapp watching Dr Gordon's house, there are clips of newspaper headlines that flash up on the screen. However, the articles themselves have nothing to do with Jigsaw or even the headline above them. (00:41:00)
Audio problem: When Dr Gordon is cutting off his foot, the screams from Adam are just a replay of the screams he does at the end of the film. (01:27:05)
Continuity mistake: When Tapp and Sing discover the Billy puppet in Jigsaw's warehouse, the puppet's head changes direction at least once. (00:47:10)
Continuity mistake: The bloody bullet wound is seen on Tapp after he's shot. When he is shown after he falls on the ground, the bullet wound is not there. (01:27:50)
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: 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.