Continuity mistake: Brad shoves the saw blade into Ryan's face in the public trap. Ryan dodges out of the way, camera does an instant cut and he dodges the saw again. (00:05:25)
Continuity mistake: When we see Cale's trap, he has got sweat stains on his shirt, in the shot from the floor, there is no sweat stains on his shirt. (00:50:30)
Continuity mistake: When police are running to the public trap, there is someone on a push bike that gets knocked into the glass. Camera changes and he hits the glass again. (00:07:25)
Continuity mistake: When the car drops on Evan's girlfriend it leaves half of her head intact. When Homicide and IA are examining the body, the head is in a much worse state. (00:21:00 - 00:28:05)
Continuity mistake: Spoiler: When Hoffman gets out of the body bag at the police station, he kills the coroner. He then hides by the wall next to the door as the second coroner walks in. Camera cuts and Hoffman is now standing in front of the second door, a good three feet away from where he was standing before. (01:08:00)
Continuity mistake: In the bar scene there is one point where an extra walks behind Bobby heading to go behind the other bloke. Camera cuts and the extra has vanished. (00:33:30)
Continuity mistake: When Hoffman kills the police officer opening a door, the door is only slightly open. When Jill gets to the police officer, the door is open much wider. (01:08:45 - 01:13:40)
Continuity mistake: In the public trap, the amount of blood on Dina's stomach is constantly changing. In one instant it goes from being almost covered to absolutely no blood. (00:07:00)
Continuity mistake: The amount of blood on Nina's face changes depending on the shot. (00:41:00)
Continuity mistake: When Joyce first sees Bobby, in one shot both hands are on the collar round her neck. In the next shot one is halfway down the chain. (00:32:15)
Continuity mistake: In the garage trap, Evan can be seen to grab hold of the steering wheel with the tips of his fingers on his right hand. Camera changes, and his hand has moved instantly. (00:19:35)
Continuity mistake: When Bobby pulls on the lever to open his cage, he has one hand on the handle in one shot and in the next shot, he has both hands. Camera changes, and he's back to one hand. (00:31:20)
Continuity mistake: When Bobby says it's his fault, he has both hands up. When the camera changes, his right hand is down by his side. (00:15:45)
Continuity mistake: In the garage trap, Evan is reaching through the window with about 12 seconds to spare. The camera changes, and his reach is nowhere near as far as it was before the camera change. (00:20:25)
Continuity mistake: Just before Nina dies, Bobby covers her mouth with his right hand, and holds the side of her face with his left. When he does, his hands are apart. Camera changes and his hands are now touching. (00:41:00)
Continuity mistake: Bobby presses play on the publicist's tape. However in all other shots the play button is not pressed. (00:39:10)
Continuity mistake: When we see the bear trap at the start of the film, there is a small amount of blood on the trap from when Hoffman was in it. Later, when it's left on show for Gideon, there is a lot more blood on the trap. The device is nowhere near any other victims for their blood to spill on to it. (00:09:35 - 00:28:40)
Continuity mistake: When we see the garage trap we see that half the windscreen is smashed away and the other side has a crack through it. However in one shot, the cracks have gone. (00:19:10)
Continuity mistake: Hoffman does Jill's second wrist restraint up. Camera cuts and he does it up again. (01:15:20)
Continuity mistake: Bobby finishes the tooth room with 14 minutes to spare. When he's in the next room he only has 4 minutes left. (01:03:00)
Answer: He, his wife and his daughter were abducted before he decided to work with Jigsaw. He didn't put them in danger. As for why he decided to work with Jigsaw following his ordeal, like other characters in the franchise, he either developed a level of Stockholm syndrome or he concluded that Jigsaw's methods were right, or a combination of both.
Phaneron ★