Audio problem: After the aeroplane crashed, a dinosaur stepped over it and the windows shattered making the typical sound of made-of-glass things when broken. They are made of plexiglass (a sort of fibrous plastic).
Audio problem: When Sidney comes running to the house and she sees Dewey come out with the knife in his back she screams "Dewey!" but her mouth says "no!" (01:23:45)
Audio problem: At the beginning, when they steal the dolphin, you hear the peel-out sound effect as if the truck was on a paved road, but they were on grass. (00:07:15)
Audio problem: When the Terminator breaks into the police station, he has an auto-shotgun in his left hand, and a machine gun in his right. Before he kills the power in the building, he comes to the end of a hall, points his shotgun through a doorway, and shoots. A machine gun sound is used for the blast, instead of a shotgun sound. (01:00:28)
Audio problem: In the scene where Leo explains how he launders the drug money and Roger says "You're a cheat", Leo says "Come on, everyone cheats a little, look at the pentagon." But when he says "look at the pentagon", it's dubbed in because the sound of his voice doesn't match his other dialogue, and if you read his lips it doesn't match either.
Audio problem: When they arrive at "The Magic Carpet" you can hear Izzy drag three heavy bolts across the door, when the door opens, there are no bolts - just as well, otherwise shooting the lock wouldn't have worked. (00:56:30)
Audio problem: Just as McClane and Farrell are about to leave the Eastern Power Hub, Farrell goes on a long rant and his mouth does not match the words he is saying. [In the unrated version of the film, the rant concurs with Will's mouth movements, but the mistake is valid for the regular version.]
Audio problem: In the scene with John and his friend in the garage when his adopted mom is telling him to clean his room and he is revving his dirtbike, if you look closely, he has the throttle wide open, but the motor winds down. (00:12:15)
Audio problem: An early scene in the movie has Chinese soldiers recruiting Tibetans to work on a secret project which they are told is a dam. As the scene ends, the sound of explosives draws everyone's eyes towards the mountains, where the explosions can be seen several miles in the distance. The sight and sound of these explosions take place simultaneously. Sound travels much slower than light. In reality, there should have been some delay before the sound of the explosions was heard.
Audio problem: When the Knights deploy their missiles with no results, we see in close-ups as they respond that Steven is Knight 1, Jimmy is Knight 7, and another Marine is Knight 3. After Steven says, "Knight 1. Sweet Luck. Echo, Fox 2," we see a close-up of Knight 3 and hear his voice (not Jimmy's) say, "Knight 7, Fox 2", though he is in fact Knight 3, and Jimmy is Knight 7. (01:00:45)
Audio problem: A soda can that is supposed to be full hits the man. When the can hits the ground you can hear that it's empty.