- Continuity: When Matthews' friend, Michael, is watching the puppet explain his situation on TV at the beginning of the movie, the channel indicator on the television keeps changing from displaying channel 3 in one shot to being covered up with duct tape in the next.
- Crew or equipment visible: As the police first arrive at the warehouse, several crew-members' reflections can be seen in the sides of the police vans.
- Continuity: Rigg's earpiece disappears between shots.
- Continuity: When they discover Obi's envelope, the knife's position on the envelope shifts between shots.
- Continuity: The wounds on Amanda that were inflicted by needles in the pit that she was thrown into by Xavier disappear and reappear throughout the rest of the film.
- Continuity: When Detective Eric Mathews meets John his badge is normal. A few moments into the scene it becomes twisted and when it cuts to John then back to Eric after a second the badge is normal.
- Factual errors: A swat member uses a battering ram to open the outside door of the facility, but it is a door that opens outwards.
- Continuity: The pool of blood from Gus's gunshot wound changes when Daniel goes to put the coat over his head.
- Continuity: When the Tech Team arrives you can see the clock as the detective is destroying Jigsaws work saying 8:00. It had been seen earlier in the movie saying it was almost 8:30.
- Continuity: When the SWAT team have their guns aimed at Jigsaw's heart (just after Matthews says "Hey - is this close enough?", we can see three laser guides on his chest. Then one of the SWAT team members points his gun down, but there are still three laser guides on Jigsaw's heart. Seconds later there are two lasers, then three again.
- Continuity: When Xavier opens the door to the Syringe Pit, it shows a very short clip showing the timer on the door for the antidote. If you slow the clip down, you will see that the timer shows '4:00', in the next scene it shows '2:58'.
- Audio/visual unsynchronized: In the needle room, when Addison screams and says "Stop this shit!", her lips are saying "Fuck this shit!"
- Revealing mistakes: Det. Mathews throws Jigsaw on the floor and you can tell it's a dummy by his stick-thin right leg.
- Continuity: The first time we see the number 9 on Addison's neck, it has a curvy line, looking like an upside down 6. Later, when there are flashes of the previous numbers, the 9 shows up with a straight line.
- Continuity: Before Xavier finds out about the numbers on the back of everyone's necks throughout the movie you can clearly see several times that he doesn't have a number on the back of his neck.
- Continuity: Gus' tie changes from being sloppily pulled to the right in select shots as they wake up and then being straight in other shots.
>>> WARNING: Here Be Spoilers <<<
Goofs below here contain information that may give away important plot points. You may not want to read any further if you've not already seen this title.
- Revealing mistakes: SPOILER: When Gus is shot through the eye, the bullet goes through his left eye and has a pattern of blood running down his face, yet later on throughout the movie, when Xavier sees the number on the back of Gus's neck, we see Gus's eye is perfectly normal with no blood marks, or bullet wounds.
Related Links