Other mistake: When Owen first meets Dodger, and asks if its that obvious he's a transfer, she tells him "It's a small school, word travels fast." During a flashback to this scene at the end of the movie she says "word spreads fast," instead.
Other mistake: Michelle Rodriguez's accent changes several times, not only throughout the movie, but sometimes within the same scene.
Other mistake: When the zombies come out of the river and start marching, look closely. The first zombies to come out wear wet clothes, but the ones in the back are dry.
Other mistake: The drip-meter that is supposed to administer Jigsaw's medication is not turned on. Anyone who has spent time in a hospital and seen one for real knows that a lot of numbers are shown on the displays when it is running to show medication status. (00:13:50)
Suggested correction: It's not specifically stated that the machine is in use. That's just an assumption. It could be set dressing he's using to enhance the perception of his condition.
Other mistake: When Ben lies wounded in the open, we are treated to a solar eclipse followed by a full moon. These events must be 2 weeks apart. Long enough for Ben to have grown a beard (which doesn't happen), but too long for him to survive without water.
Other mistake: When Amy first goes into Marla's apartment, she sees that the food in the kitchen is spoiled; there is a few weeks worth of mould on the scattered dishes and the food on the plates by the sink is especially bad. Yet on one plate by the sink, there is a piece of bread still perfectly white and free of decay, though it is surrounded by other mouldy scraps. The shot is only visible for a moment.
Other mistake: The chaingun was actually a heavily dressed up Browning Browning Model 1919 machine gun with a fake rotating barrel cluster surrounding the real firing barrel - in several firing scenes a careful eye will notice the barrels are not even rotating.
Other mistake: In the hospital scene at the beginning of the film, the cardiac monitor is showing no activity, after she pulls her leads, and the monitor is featured so prominently there is still no activity.
Other mistake: Towards the film end, when George climbs up stairs with the gun to kill others, he walks into the passage and shuts the door. A mirror is there in the passage, but there's no reflection of George in it. (01:15:15)
Other mistake: Covering the victims' bodies with layers of wax would make the figures look unnatural large. And the machine that secured the victims in seated position as it sprays then with layers of hot wax would mean the figures would have to stay in seated positions when completed.
Other mistake: In the scene where John is in the apartment with the cat and Angela closes the door, John then says her name to get her to reopen the door. He says the wrong name, "Rachel" (the actress' name) instead of "Angela" (the character's name).
Other mistake: When we see Middleton's bootprint, there is only one. There should be more than one bootprint as he goes along, even from one boot, as he walks toward the group to rejoin them.
Other mistake: About halfway through, the divers go into water with a very strong current, and yet both Catherine and Nicoli both call Tyler to come to them, which is impossible - the current is too strong for Tyler to even attempt to turn around and go back to them. Both Catherine and Nicoli are in the current, so they will come to Tyler, eventually, when the current isn't so strong and Tyler can hang onto something and wait for them.
Other mistake: Towards the end of the film Bill Owen digs out a entire grave in the middle of winter, in frozen ground, in a matter of a few minutes.
Other mistake: After the Joker has become a vampire, you can still see his reflection in metal poles and such while he is chasing Batman in the bloodbank. (00:47:00 - 00:49:00)