Audio problem: When the cop saves the girl from the mob of locals, his car tires squeal as he accelerates away, but the car is on loose dirt, which makes the squealing impossible.
Audio problem: Before they leave for Mission City, Lennox tells Keller, "Sir, you gotta figure out some way to get word out..." Then in the next shot, as Lennox shouts, "Let's move!" his mouth stays open - not forming the "m" with his lips to produce the word "move", which we hear very clearly (it looks as if he really said, "Let's go!"). Changes in dialogue are done during ADR and often are not in sync with mouth movements seen onscreen. (01:45:45)
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: When Dakota and Jerrod start having sex, Aubrey's mother can hear Jerrod's moans through the ceiling. But up until they *really* start getting into the act, the moans that Susan is hearing don't match the shots in the bedroom.
Audio problem: During the scene where he is hitting golf balls off of the ship, he is hitting an iron. For anyone who plays golf, the sound that goes along with this is that of a driver or some type of fairway metal.
Audio problem: In the scene where Doyle, Scarlett and the kids jump into the Volvo estate to escape the gas and infected, a number of references are made to the car having a manual gearbox, i.e. "pop the clutch". Doyle puts the car into second gear and several shots of the gear lever are shown. However, when Doyle push starts the car and they drive off, listen carefully and you will hear the distinct sound of the gear change of an automatic box.
Audio problem: Harrison hears Ro's phone yet it's on silent mode.
Audio problem: After Bert is shot in his car, when Bobby pulls up beside him and shouts, "Pop, pull over!" for the first time, in the next tight close-up of Bobby's face he is still shouting, but the only thing we hear is panting, until the next side shot. (01:17:00)
Audio problem: When Jim and Grace steal the sheriff's car and drive out of the parking lot quickly, the tyres of the car squeal on the ground, however the ground is just dirt and dust so the tyres shouldn't have squealed. (00:45:55)
Audio problem: When Anton Chigurh challenges the gas station proprietor to a coin toss, at a certain point he says "It's either heads or tails." If you listen carefully it's clear that the phrase said by him has been dubbed.
Audio problem: When the rider is posing as a doctor and is checking Will's foot, he says, "Hmmm, I wonder. Mrs. Stanton, do you have a tape?" and yet his lips never move. (00:34:00)
Audio problem: Justin Chatwin's character wants to kill himself. He grabs a breakaway double-barrel shotgun off the gun rack and steps around the corner. Then we hear a round chambered in a pump shotgun. (00:43:40)
Audio problem: Tom is in the van, after dropping off his daughter, and he "redials" a number on his cellphone but we hear the electronic beeps for each number being dialled, even though redialling on cellphones does not produce those sounds.