Continuity mistake: David calls Connie at the White House and she walks toward the divided pane windows, then pulls one curtain to the side. In the exterior shot facing her, the pane's white grille is between the two sides of the curtain, but in the next interior shot looking out, there's only clear glass, though we should see the grille, just as we see both sides of the curtain with her hand holding the right side. Then, in the next exterior shot facing her, it's back to the original with the visible white grille. (00:38:25)
Continuity mistake: When Nicolas Cage drives through the window in the yellow Ferrari and the shot changes, he is coming out from a different window than in the first shot. In the first shot he emerges from the window to the left of the 7th Street Garage storefront ('Classic Autos' written on the window), but next shot he emerges from the window to the storefront's right. Also, note the now glassless window to the storefront's left, due to a previous take.
Continuity mistake: When Matilda makes the chalk write the message on the blackboard, the writing changes. Watch the "Agatha," especially. The handwriting changes and the comma changes length, as well as most of the message changing. Also at the end of the message Matilda "writes" two long lines under it, which cross over. Yet later when Miss Trunchbull flies off the globe you can see there is just one line under the message, not two. (01:20:20 - 01:23:00)
Visible crew/equipment: When Bill's fiance is driving over after the first tornado, when the truck lands, she swerves and she stops. As she is getting out, a camera is visible. When the camera backs up though, a crew-member pulling it back is visible in the door.
Factual error: In the scene where Picard opens a viewing port and shows Lilly that she is in a starship orbiting Earth he shows her New Guinea and Australia. New Zealand is missing. (00:42:45)
Suggested correction: Actually when you look at Australia and New Zealand from orbit, New Zealand is a lot further away from Australia then shown on a map, also a lot more south of Australia. A map is a 2D image of a sphere, causing proportions to be off (its well known Africa is a lot smaller on maps than it is in real life). Especially the further south or north you go distances are way off. The depiction shown in the movie is actually correct, in that angle New Zealand is just outside of the frame. There are plenty of pictures from orbit to compare.
Other mistake: Near the end of the closing credits, when the Warner Bros. Copyright appears, you'll see the very first word "All" spelled incorrectly as "Al" in "All material is protected by Copyright Laws of the United States and other countries throughout the world." (01:26:40)
Continuity mistake: As Beavis and Butt-head are dancing in the casino the floor is just flat and one surface. In the overhead shot of them dancing you can see part of the floor has changed to an tiled area instead of a plain flat surface. Also there are a number of people sitting at tables just in front of them whilst dancing. In the overhead shot they and the tables have disappeared. (00:21:30)
Continuity mistake: In the scene with Sinbad and Howard in the radio place, Sinbad gets enraged, then throws the package (thought to be a bomb) and Howard hits the deck. The package lands at Howard's head, but in the next shot, it's way over to his left.
Continuity mistake: In Escape from New York, Snakes tattoo on his stomach is filled in. In Escape from LA, his tattoo is just an outline. (00:18:05)
Revealing mistake: The natives use a pair of nooses to trap the bad guys, but when they're lifted up, one can see the protruding hook and mechanism under their shirts.
Visible crew/equipment: At the end of the film, when the news about the train and helicopter accident plays on the TV, as the camera pulls out, the camera's reflection is visible in the blue window shutter. (01:44:08)
Continuity mistake: Before Draco lifts up Bowen his grip on the cable changes between shots.