Other mistake: When Andie goes over to the diamond display (at the party) she isn't wearing any jewelry, and touches her ears a couple of times, demonstrating there's nothing on them. Later on she is seen wearing 'Isadorra' (the yellow diamond necklace) and a pair of matching earrings, which are certainly large and sparkly enough that they would have been visible if she was wearing them earlier. When security chases after Andie after she leaves, they only take back the necklace. I guess that the diamond earrings weren't that important. (01:39:30)
Other mistake: Marvin survives the explosion by hiding in the refrigerator, though despite the massive blast, there is no singeing, burn marks, or even smoke around the holes that were torn into the front of the door before the explosion.
Other mistake: When Will and Lori get out of the Lake at the end, Lori's arm isn't burned. It's only scratched.
Other mistake: After Gollum attacks Frodo and Sam on Mount Doom, Sam fights Gollum off with his sword. He then turns around and calls out for Frodo. There is a brief medium shot of Frodo scrambling up the mountain (at about 01:20:35 on disk 2 of special edition). If you look carefully in the background, you can see snow and running water in the background. This is common on Mt. Ruapehu, where the scene was shot, but a bit out of place on Mt. Doom. (01:20:35)
Other mistake: When Kimberly gets in the ambulance at the hospital to drive it into the lake she shifts it upward instead of downward to go from park to reverse.
Other mistake: When Will's mother steps into the bathtub where his father is already lying in, the camera switches between both persons and the water level (in relation to the bathtub edge) on each person's side is on a different height. Yet when both persons are shown, we can see that the bathtub edge is fully horizontal, so the water level should be the same on both sides. (01:25:00)