Factual error: The hat that Brad Pitt wears in the 1985 scenes is a Padres hat with navy, orange and white as the colours. In 1985, the Padres' colors were brown and yellow. The color change didn't come until late 80's or early 90's.
Factual error: Amongst the essential parts of a nuclear weapon's detonation mechanism is a radioactive isotope of tritium, which has a half life of just 12 1/2 years. The tritium in every nuke on earth has to be replaced every ten years or so. This is by no means unusual; there are other perishable parts including detonators made of conventional explosives which would be completely inert after a thousand years. After lying dormant with no maintenance at all for that amount of time the nuclear weapons the 'Man-animals' find would be big shiny paperweights and not much else.
Factual error: When the bombs are being taken down the lane, in the background where the lane meets the road a white mini can be seen passing the entrance.
Continuity mistake: The owner of the Cleveland Browns drives from NYC to the Teterboro Airport (12 miles from Midtown Manhattan), flies to Cleveland (450 air miles) and drives to the Browns facility (16 miles) in the time it takes the 2nd, 3rd, 4th and 5th picks in the 1st round of the NFL draft to be made.
Factual error: Listening to a radio broadcast, live, since no other indication is given, Joe Louis is completing the 12th round of a fight. This is December 6, 1941. Joe's last fight of 1941 occurred in September, his next fight was January 1942. (00:00:10)
Continuity mistake: When swimfan85 is trying to talk to Ben and he tells her he has homework to get done, she is talking with the nick name swimfan85 but when she signs off it says "swimfan has signed off." They forgot to add the 85.
Continuity mistake: In the final scene where Roxie and Velma are dancing in the concert hall, Roxie is on the right and Velma is on the left. They then turn around, and from behind (same point of view as before) they're suddenly the other way around. (01:44:20)
Factual error: It is not possible to be "allergic to all known anaesthetics". Amongst the amide local anesthetics lidocaine, prilocaine, bupivicaine, mepivacaine and dibucaine are naturally occurring substances and if administered without a preservative they cannot trigger an allergic reaction. If Bales is allergic to them, he'd be allergic to the metabolic processes of his own body. They are all powerful local anaesthetics and could easily be used for a radical rhinoplasty such as that required by Bales.
Continuity mistake: There is a scene where the Chipmunks and Chipettes are singing the song "Girls of Rock and Roll." In that scene, it shows the boys walking up the stairs together and from left to right the order is: Simon, Alvin & Theodore. The shot goes to the girls then back to the guys. The order of the guys has switched: (left to right) Theodore, Alvin & Simon.
Audio problem: In the scene after Reese Witherspoon and Luke Wilson are returning from questioning the ex-wife of the murder victim at a spa, they are driving up in Luke's car. You can clearly see, as they get closer to the camera, that what you hear Luke saying isn't what his lips are saying. It was a very obvious dub over...and a very bad one.
Visible crew/equipment: After Josh tells Cher she's such a brat, at the start of the next shot which is the first close-up of Cher during the driver's test, just as she says, "I had an overwhelming sense of ickiness, even though I apologized to Lucy," the top of a crewmember's head, with his short wavy hair blowing in the wind, is reflected at the bottom of the Jeep's windshield, directly in front of Cher and the steering wheel. (01:11:55)
Factual error: Towards the end of the movie when Andy is escaping, he breaks open a sewage pipe and is covered with its contents. It is physically impossible for the sewage to shoot out of the break like it did. In order for that to happen there has to be pressure. But there is none there, because the end he crawls through is empty and the end is in the open air. (01:52:20)
Audio problem: When Commander Taggert (Tim Allen) and Lt. Madison (Sigourney Weaver) first see the hallway with the chompers, she says, "Oh, screw that!" but if you watch her lips she clearly uses the 'f' word instead of 'screw'.
Continuity mistake: There are two scenes during which Harry is shown having visions of the Dept of Mysteries while he is asleep. The first scene occurs after Harry's confrontation with Seamus in the Gryffindor common room. There are shots of Harry lying in bed wearing a short sleeve, crew neck tee shirt, but when he is startled awake by the vision of Voldemort, he sits up wearing a buttoned henley tee. The next day is the first day of Defence Against the Dark Arts class with Umbridge. That last shot of Harry in the henley tee shirt was cut from a later scene. Later in the film, when Harry has the vision of Arthur Weasley's attack, he is wearing the henley tee shirt. (00:34:00 - 01:09:35)
Continuity mistake: When Uma Thurman visits the radio station for the first time, she asks Janeane Garofalo if she can sit down by the microphone. As she's standing in front of the desk she's wearing a cardigan with a handbag over her shoulder. When she turns round to say "you promise not to laugh?", the cardigan and bag have disappeared. (00:16:10)
Continuity mistake: During the Xmas day scene, Markus receives a Sony portable CD player as a gift from Will. However, before the gift's unwrapped, the Sony box is visible on the table. (00:51:45)
Factual error: The video games Operation Wolf and Rampage were visible in the Family Amusement Center arcade during the opening. However, this would not be possible during the movie's 1984 setting since Rampage wasn't released until 1986 and Operation Wolf wasn't released until 1987. (00:12:48)
Factual error: The 15 bus in London does not go over Westminster Bridge.
Other mistake: In the slaughterhouse scene, after Harrigan has injured the Predator with his shotgun and Keyes reappears, the Predator throws its disc, and severs Keyes in half at the waist. We see his legs flop to the ground, and blood pour from above, but his upper half (torso, backpack and weaponry) mysteriously remain hovering out of sight. (01:21:50)
Factual error: Most ventilation ducts are not large enough for a person to crawl around in, and any duct large enough for an adult to fit in wouldn't be able to support the person's weight. In the rare event that a company could afford a large ventilation system that could support a person's weight, they would likely forgo it anyway, as it would pose a security risk.