Factual error: At the end of the film Rainwood has established his innocence of the drug charges and is happily back at work as a senior mechanic for a large airline. However, part of the sentencing and plea bargain protocols at his arraignment is his previous conviction on a lesser drug charge years before. It goes without saying that he did not advise his employers of this when he started work for them - no airline in the world (even pre 9/11) would hire someone with a drug conviction on their record! Now this is out in the open the airline knows that Rainwood is a convicted drug user (on the lesser, legitimate charge) and that he lied on his original job application. They wouldn't hire him again to sweep the floors.
Revealing mistake: In the catacombs of the library, Indy and Elsa are waist deep in petroleum. Indy has a torch, and if you look carefully, you will see burning pieces of the torch fall and hit the petroleum. Wouldn't this start a fire as Kazim later on sets the cavern alight with a single match? (00:34:05)
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.
Continuity mistake: Notice Marty's hair in the scene when he's playing "Johnny B. Goode." It's quite larger than when he says, some seconds later, "I guess that you're not ready for it yet." That's because when he says that, it's a recycled shot from the original BTTF, whereas most shots showing he's playing the guitar are newly made for BTTF2. However, Marty's hair is considerably longer in the new shots.
Continuity mistake: Early in the film Bud throws his wedding ring down the latrine and then retrieves it with his right hand so it is covered with the blue disinfectant. In a (much) later scene, Bud has a blue right hand, despite not having had one in the intervening period. (01:44:48)
Other mistake: Sergeant Johnny Gallagher (Gene Hackman) and Lieutenant Milon Delich (Dennis Franz) are in a supposedly deserted building searching for a group of conspirators who plan to assassinate both the USA and USSR presidents. Delich finds a police colleague of his in the building, and Delich kills his colleague. When he fires his revolver, the sound of the blanks can be heard, slightly out of synch with the gun blasts on the sound track.
Continuity mistake: When Stallone stops the bad guys in the semi full of cocaine, they fly through a windshield that is apparently made of plate glass, and not the safety glass found on almost every other vehicle windshield on earth.
Other mistake: When Miyagi throws Mike into the light switches, the lights go out but the switches never change position.
Continuity mistake: When Beck meets Webly on Christmas Day, Webly takes his glasses off and throws them on the desk, but in the next shot (from behind) he is still wearing them. (00:16:50)
Continuity mistake: In the scene where Belushi and Jerry Lee (the dog) enter the warehouse, Belushi askes everyone to stop what they are doing and even has the forklift driver lift him up so he can talk to them. Once he is done talking, he tells the lift driver to bring him down. The next few shots where they show Belushi walking to his car, if you look closely, you will see that the fork lift is back up in the air, but there were no sounds and there isn't another lift to be found. (00:25:05)
Continuity mistake: Towards the end of the movie Dave takes Walley's jacket and uses it to help them slide down a cable. Before they slid down, Dave tells Walley to hold on, and Walley asks if they're going to be above the ground. Dave tells him no, and off they go. However, Dave is deaf, and reads lips, and Walley is standing behind him when he asks the question. So how did Dave read his lips if he wasn't looking at him?
Revealing mistake: In the scene after the battle of Agincort, where Henry and his retainers are walking meditatively among the heaps of the fallen, if you look carefully, you will see one of the fallen with his head raised watching the procession. He then realizes that he is on camera and puts his head back down. It's near the edge of the screen so may occasionally be cropped.