Revealing: when Eric Matthews is smashing his foot, he hits it the first time and it shows a close up. If you watch the small amount of blood when he hits it again they have used the same shot.

Continuity: Just before Amanda shoots Lynn her gun switches from her right hand to her left.

Continuity: Lynn is in the corner of the room when Amanda is threatening her with the gun. The shot moves to behind Amanda when she raises her hand to her head and now all of a sudden Lynn is a good 4 or 5 feet to her right. (instant cut, not enough time to move).

Continuity: The drill that Lynn uses on Jigsaw's skull has a white piece of tape on the end of the drill bit a short distance from the end, presumably to mark the thickness of his skull so she knows where to stop. In one shot (during the drilling scene) the piece of tape moves a good two inches farther up on the drill bit, but it's back down in the very next shot.

Continuity: Right before Lynn says "I don't know what you know, but my marriage has survived more suffering that you could possibly imagine" her hair is all pulled back behind her ear. As she's saying that line you can now see that a noticeable amount is hanging on the side of her face and across her ear.

Continuity: After Lynn looks for pills she runs back over and tells Amanda "Back off, back off", then takes off Jigsaw's oxygen mask and puts her hand on his face to keep his head to the side and you can see two drops of blood on her hand. The shot cuts to a closeup of Jigsaw and now there is no blood on her hand.

Continuity: The tear in Jeff's face (after he gets stuck to the refrigeration machine) continually changes throughout the movie. It goes from oozing and bloody, to clean and almost normal looking several different times. There's no blood on his bathrobe, so he didn't wipe it off that way. That's a big enough tear to bleed a decent amount, so we'd see the blood if he wiped it off.

Continuity: The glowing "X" on the bathroom wall in the first Saw movie was very symmetrical, and the whole thing was filled in very well. During the Saw III bathroom flashback scene, when Jigsaw paints the "X" it's completely different that the one that shows up in Saw. It's not symmetrical at all, and the paint doesn't go on very thick at all. You can easily still see the wall behind the paint, but in Saw, the lines of the "X" are very full with no gaps.