Other mistake: Beethoven didn't seem fussed nor resentful of Napoleon being part of the group. Historically he temporarily admired him and wrote the Third Symphony inspired by Napoleon's ideals of Europe's new hope of enlightenment but later despised him after he crowned himself Emperor of France in 1804 and furiously scribbled out his name off the title page of his Third Symphony and named it Eroica which he originally titled it as "Bonaparte Symphony" due to his former admiration of Napoleon.
Visible crew/equipment: After Indy and Henry have escaped from Castle Brunwald, Indy jumps into one of the boats, pulls the motor starter cord and jumps back out, then just as he bends over to release the boat from the piling, right between Indy's legs the black covered arm of a hidden crewmember appears from under the tarp taking hold of the throttle, steering the boat away from the pier. (01:02:40)
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. (01:27:19)
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)
Factual error: When the air hose on the truck is severed, the brakes release. In reality, on an air-braking system, if the air hose is severed, the brakes lock on as a safety measure.
Revealing mistake: When Nick is being sucked out of the hole/cave, you can see the wires visible from his waist. (01:20:35)
Continuity mistake: When Vigo throws the streams from the proton packs back onto the Ghostbusters, there is a wide shot of Egon getting thrown way over to the right. However, when they do a closer shot, he is way over to the left, closer to the other three Ghostbusters. (01:33:50)
Continuity mistake: At the patch ceremony, Chica goes over to Phyllis to get some food and she has her patches on. The patches weren't given out until the next scene.
Continuity mistake: Bernie's facial expression changes from the smile on his face when he first get injected with drugs to a smirk throughout the movie, to no expresssion and back again.
Revealing mistake: During the Hy Brasil sinking sequence you can see a horizontal line in the water in the background, this is the edge of the water tank they used to film this sequence. It's also visible in several shots from the longship.
Character mistake: In the finals of Video Armaggeddon the compere keeps making comments such as "Jimmy loses a life and starts over in world two", "Laura finishes world two", "Lucas finishes world two". All three times the relevant person is actually in World 1 - Level 3. In Fact at no point are any of the competitors in World 2 and the only time any of them is out of World 1 is when Jimmy uses the warp to access World 4.
Continuity mistake: When Wallace races to get crackers, check the packet's logo. When the camera angle changes it's different. (00:08:57)
Continuity mistake: When Brian spends his first night in the underground monster world he goes in wearing a shirt and boxer shorts. But a later scene shows him wearing a shirt, pants, and shoes. He then goes back home and is back in his shirt and boxer shorts.
Suggested correction: It's entirely possible that he was able to borrow a pair of pants while down there.
I just watched the scene where Maurice and Brian pull the pranks to get the kids into trouble and he is in his pyjamas. Later in the monster world he is in a full outfit including a shirt, pants, and shoes. Then he goes back home and he is in his pyjamas again.
Continuity mistake: When Banner changes into Hulk in the subway station, his beard is gone. When Banner changes back after his "Hulk-out" his beard is back. (00:16:00 - 00:18:00)
Plot hole: They seem to break a lot of rules in the main event between Mimi Lesseos and Jan Mackenzie's. They brawl outside the ring long enough to be counted out, choke outs on the ropes long enough to be disqualified are some examples.
Continuity mistake: When Fuller falls to his death, the mannequin used as his stand-in gets decapitated on its way down. It even makes a loud noise. When Fuller lands, however, his head is still on his shoulders.