Continuity mistake: When Jeff is monologuing about how "Everyday for 3 years I wanted to kill him" there is a tear that appears in his right eye and starts to run down his cheek. The shot cuts away for a second, then back to Jeff and there is no tear, not even a wet tear trail.
Continuity mistake: There's a shot of the right foot when "The Rack" starts twisting it. There is a blood trail that runs off between his first 2 toes, and a lesser one that runs off between his 2nd and 3rd toes. The screen cuts to a close-up of the foot and there's only the blood trail that runs off between the first 2 toes.
Continuity mistake: The knot and string position on the tape player is different during the close up of it on "The Rack" guy's chest than it is during the far away shots.
Continuity mistake: When Jeff sees the doll on the wrecked trike you can see that the doll's hand is on the trike tire, but in later shots (of the doll from the waist up) the wheel and tire and nowhere to be seen.
Continuity mistake: The clamps on Jigsaw's head change their positions between the time Lynn says "He's stabilized" and "I need you to raise your hand and spread your fingers" The top one is most noticeable, it goes from hanging over his forehead to lying on top of his head.
Continuity mistake: The positioning of Amanda's green sheet changes drastically during her cutting scene.
Continuity mistake: While Jeff is contemplating burning his son's possessions his hair constantly changes from messed up and down, to pushed up and away from his face. One of the shots you can see Jeff put his hand to his forehead in agony, so this explains that part of the hair change, but the changes happen several times during the same scene.
Continuity mistake: The length of the cut on Jigsaw's neck changes constantly throughout the final scenes.
Continuity mistake: Jigsaw gets "blood" all over the top and sides of the lid of phosphorus paint, yet there is hardly any "blood" on it when he throws it in his bag.
Continuity mistake: When Eric slams Amanda to the wall she eventually starts bleeding profusely. But you can see that there are no blood spatters on the wall even when he continually tries to do this a few more times after that.
Continuity mistake: When Amanda is dying in the end, the amount of blood on her mouth and coming out of her mouth changes between shots. More than once the trickling blood disappears then comes out again.
Continuity mistake: As Jigsaw is dying his bed is mostly reclined and his head is lying flat, but when you see the last shot of him you can see that the head of his bed is more elevated and he's slumped.
Continuity mistake: When Amanda gets shot and falls next to the cart you can see that there is no blood on the cart. The next time you see her there are blood splatters all over it. Every time you see the cart there is a different design of blood on it, and at least one time there is no blood to be seen.
Continuity mistake: In "The Rack" room you get a shot of the box holding the shotgun and the key. When first viewed from the back the keyfob and the key are directly parallel to the front and back of the box. The scene cuts back to the guy in the rack, then back to the box. Now the key and keyfob have moved and are almost vertical to the sides (the judge hadn't started to move it yet, there's nothing to explain how or why it would have moved).
Continuity mistake: Jeff's body position moves when he's looking down the hall towards the wrecked trike. When the shot is in front of him his right leg is farther forward than his left and he's leaning forwards peering into the darkness, when the shot is behind him he is standing up straight and his feet are parallel.
Continuity mistake: During the scene when Lynn is telling Amanda that Jigsaw needs to have an operation Lynn is talking to Amanda with her body slanted forward and her head and chin up (in a "you're stupid, this is what we need" type of pose), but in all of the over-Lynn's-shoulder shots her head is tilted down to look at Amanda.
Continuity mistake: The blood smear on Lynn's cheek changes size and shaper during the scenes when Jigsaw is hallucinating and tells her that he loves her.
Continuity mistake: When Amanda dies, her left arm is outstretched and her hand lying vertically on it's left side. There is a quick cut to her body during Jigsaw's final message and you can see that her hand is lying flat on the floor, then it cuts to a close-up of her hand and it's back on its side again. (look at her watch for a reference point to her hand position).
Continuity mistake: When Lynn first gets rolled into Jigsaw's room she has a few strands of her hair in the corner of her mouth. The strands appear and disappear during the next few shots.
Continuity mistake: In the "Twisting Crucifix" device scene the tear on the man's face jumps from his right eye, to his left, then disappears, then reappears again throughout the shots.
Answer: Adam didn't just lose because he let the key get drowned. He had the two hacksaws and he broke his own in a hurry. And there was also the toilet lid that he could have used to smash his foot like Eric did in Saw III. Jigsaw never said that improvising or thinking outside the box was against the rules. So even if you wipe the key out of the equation, Adam still has at least two other ways to release himself from the chains.
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