Continuity mistake: The tape on the picture that Daniel has keeps changing. In some shots it's all nice and neat; in others it's curled up and taped to itself. (01:02:30)
Continuity mistake: Right after the guy gets shot through the door, it goes back to detective Matthew, and there is a small cut above his right eye. In the next shot it's above his left eye, then back. Meaning the shot is backwards. (00:25:10)
Continuity mistake: Jonas is listening to the tape again. When the door opens, the tape stops playing. But you don't see Jonas stop the tape, and there is more left on the tape as we have heard it before. (00:26:20)
Continuity mistake: When the people spot the envelope with Obi's name on it, the blade of the knife holding the envelope changes angle between shots. It goes from vertical to horizontal. (00:34:15)
Continuity mistake: The way Kerry is holding the files of the people in the game changes instantly when Matthews grabs the files from her. (00:56:25)
Continuity mistake: In the scene when Eric Mathews goes to confront Jigsaw (after he first looks at the monitors), the chain of his badge gets twisted when he gets held back, but as he's about to leave the chain appears, untwisted. But when he gets back to the monitors, his chain is twisted only to be untwisted by him a few seconds later. (00:16:30)
Continuity mistake: Right at the end, the amount of blood and cuts on Jigsaw's face changes when he is in the van with Det. Matthews. (01:10:30)
Continuity mistake: The position of Det. Matthews' cigarette in the ashtray changes when he's arguing with Det. Kerry about her being the "Jigsaw expert." (00:09:45)
Continuity mistake: When Det. Matthews leaves Michael's crime scene, just before Kerry says, "Look closer, Det. Matthews," his tie changes position between shots. Note the position of the knot. (00:08:20)
Answer: It was Zep, but he died because Adam smashed his head with a toilet seat cover.