Other mistake: When Adam comes in and says "when I woke up this morning, the pain was gone", Connie is mouthing his lines behind him.
Revealing mistake: When The Mask is dancing with Tina and he turns her into a human tornado while spinning her around, none of the onlookers in the crowd show the slightest bit of amazement at the impossible feat that just occurred in front of them, indicating that the extras were not directed to react to the special effects.
Factual error: There are a lot of comments about the Harrier (technically speaking it is an AV-8B, a slightly different aircraft) flown by Arnold Schwarzenegger, but everyone's missed the obvious one. The terrorist with the AK47 is unaware of the fact that a Harrier is hovering just outside the window until he slowly turns and see it there. He does a double take when he sees the Harrier just five metres away! A Harrier is an incredibly loud aircraft; you can hear them from three kilometers away. At that range the floor would shake with the noise and he would have been in no doubt whatever that he had been under attack for some time.
Continuity mistake: In the movie Christie Swanson drives a BMW 3 series coupe. In the scene where they were making love the car suddenly changes to a four door model then back to a two door. (00:06:10)
Continuity mistake: After the Ballet, Alfalfa is being chased by the two bullies and Alfalfa is carrying a handkerchief that Darla gave him. He dives into someone's pool and swims across. When he gets out, he picked up his underwear but the handkerchief is gone. In the race, he has the handkerchief back.
Revealing mistake: Signs for Baltimore based businesses are clearly visible in the stands, such as "Sheraton Inner Harbour" and various Baltimore banks.
Visible crew/equipment: When Francesco and 'she' are in the cemetery together and the little blue flame-beings gather around to watch them, you can see the wires they're suspended on several times. This is most apparent when Francesco sees the first one (moments before seeing 'she' at the fountain) and also just before they are all frightened away. (00:17:30 - 00:20:40)
Plot hole: In the Cowboys' last possession of the final game, Spike makes a long run before being stopped on the goal line. The Cowboys' next play is a run up the middle. The Little Giants stop the run and the Cowboys lose possession, but since that was the first possession of a new set of downs, the Cowboys would have three more chances to score.
Continuity mistake: At the wrap party for "Bride of the Atom," when Dolores starts screaming at Ed "These movies are TERRIBLE!" her hair is curled in ringlets that hang down to the tops of her shoulders. She then stalks out of the warehouse, and Ed follows her. When he catches up to her in the parking lot, and she tells him she is leaving him, you can clearly see that her hair is suddenly much shorter and curlier.
Factual error: In the opening shot of the film, a big oak door opens - carved in it is the date 1862 - 42 years after George III died.
Continuity mistake: In the scene where the Spaniard is beating up all the guys that Maverick paid off he ties one guy's neck to a post with his whip. As the shot changes you see the whip go only around his neck, but in the last shot of the scene it's around neck and post again. (00:36:00)
Deliberate mistake: Twice in this film Axel is shot at by multiple gunmen using automatic weapons at close range - and they all miss. In the Earthquake theme ride the bullets ricochet of the rails at Axel's feet. Why are they all aiming low? Why don't they raise their aim? In the park outside he hides behind a perfectly ordinary park bench and the bullets hit the wooden slats. Not one goes through the open spaces between them? I know bad guys can't shoot straight in the movies, but this is ridiculous ...
Continuity mistake: The white gloves Corrina is wearing standing at the front door of her boss' house appear and disappear.