Continuity mistake: When Seth has been sliced by the blade, he spits blood that goes all over his face. It then cuts to Hoffman looking at him, then back to Seth, and now the blood on his face has gone. This happens three or four times. (00:05:10)
Visible crew/equipment: In the crushing room at the end of the film, Strahm is trying to open the box where Hoffman is. As it's descending into the ground, on the side of the box you can see the feet of a crew member with white sneakers moving around. It is not Strahm's feet: he's wearing black boots. No slow-mo is required.
Continuity mistake: The air hoses attached to the glass box at the end of the film are hanging straight down in some shots, and are wrapped around themselves in others, without anybody touching them.
Revealing mistake: When Strahm's phone says "no signal" there is actually a three bar signal. (00:06:35)
Continuity mistake: The air hoses at the end of the film keep changing position. There is a shot from above: the air hoses are below actually resting on top of the glass box. Then when Strahm is trying to get out through the roof, there is a small rectangle cut out of the grated mesh and the hoses are above the roof and are not resting on the box anymore.
Other mistake: Virtually all the text in the various articles and reports in this movie are fake. Look at the John Kramer article at the very beginning, even at first glance you can tell it's an article about pilgrims or something and has nothing to do with John Kramer. Also, when Staham is going through the articles he found on Hoffman's sister, you can very plainly see that every article (there are a few) is just the same typed out story copied and pasted into various formats. (This doesn't even require slow motion, just pay attention.) (00:11:45)
Plot hole: Hoffman is able to implicate Agent Strahm as the mastermind behind the main series of traps in this film by planting Strahm's cell phone at the scene. However, Hoffman is repeatedly shown to be touching things at the scene without wearing gloves, so a forensics sweep of the crime scene afterwards would show Hoffman's fingerprints all over the place and reveal him to be the actual mastermind. Agent Erickson arrives at the crime scene before the two survivors of the traps complete their tests, so the forensics team would have been called in before Hoffman had a chance to remove any evidence that would incriminate himself. As a forensics officer himself, Hoffman should know better.
Revealing mistake: When Strahm removes his jacket at the end of the movie and starts pushing the walls with his hands and uses his legs, when he takes his feet off the wall, the wall moves. Now considering these walls are supposed to be solid steel, this doesn't make sense. The walls are actually wood.
Other mistake: When Agent Strahm first starts investigating, he uses the FBI computer to look up Seth's name. He is heard typing many more characters, very quickly, than actually show up in the 'search' field on the screen. (00:29:20)
Continuity mistake: After the first room bombs go off, all the people are crouched on the floor and there is a load of dust. Camera shows Billy, then the people again. Now, there is no dust and everyone is stood up again. (00:35:05)
Continuity mistake: When Jill is talking to Erickson, the height of the key on her chest keeps changing. (01:03:10)
Continuity mistake: Throughout the movie, the clocks show incorrect time and at times changes from 8:20 to 18:20 and the countdown clock shows wrong sequencing. (01:01:00)
Continuity mistake: When Hoffman has the orange blanket put on him by the paramedic after escaping the Gideon Building, she puts it on him twice. It is also at one point not covering his right shoulder, but in the next shot, when Fisk talks to him, it is. (00:11:00)
Continuity mistake: When Strahm looks at his phone while locked in the sick room, the signal bar is on the right and the battery signal on the left. When Hoffman plants Strahm's phone in his hideout to frame Strahm, the signal bar is now on the left and the battery on the right. (00:06:40)
Suggested correction: Battery is always on the right, signal is always on the left.
Continuity mistake: The tape recorder changes position in the final game. After the walls start moving in, Strahm drops the tape recorder and it is facing the door, completely straight. When he goes and gets his gun to shoot the box, it is on a slant now. Strahm didn't move it.
Visible crew/equipment: When Strahm goes to get his gun in the crushing room at the end of the film, a boom mic is reflected on his jacket.
Other mistake: Seth is told that in 30 seconds the pendulum will drop low enough to cut his body and in 60 seconds it will cut him in half. We then see the clock start ticking. After Seth has crushed his hands, we see the clock - 46 seconds have passed and yet the pendulum hasn't cut him yet. (00:04:35)
Continuity mistake: When Strahm looks at the file and says "got you" he points at the 4th record on the list. Camera cuts and now he's pointing at the 6th. (00:29:10)
Continuity mistake: At the very start we see Seth with the collar round his neck, connected by a bolt. When the collar opens at the end of the trap, the bolt has disappeared. (00:02:20)
Continuity mistake: In Seth's trap, the mechanism that is connected to the hand crushers is moving one way and then stops. When it continues, it continues the same direction. However the hand crushers now go up. (00:04:30)
