Continuity mistake: In the 'Gaston' song sequence, near the end, Gaston is sitting in his huge antler chair with Lefou. In the wide shot, there is a bear rug behind the chair. The camera does a close up of Gaston, then in the next wide shot, the chair is on top of the bear rug. Also, after this, Gaston gets up off of the chair and in the next shot, both the chair and the rug disappear completely. (00:29:20)
Continuity mistake: When Smee gives Hook his nightcap drink, Hook takes it in his hand and holds it at the top of the goblet so that it is hidden under his hand. But in the very next shot he is holding it by the handle and the whole goblet is now visible with a small black umbrella sticking out the top. Additionally, the position of the small umbrella that sits in the goblet changes a few times. (01:02:40)Hamster
Continuity mistake: The king's youngest daughter climbs down a wall and drops a tightly sealed Erlenmeyer flask (invented centuries later) filled with a toxic potion. The flask is full when it is dropped, but partly empty after it has been caught and handed back to her by her spouse's earlier visitor. (01:08:40)NancyFelix
Other mistake: Just before the evil robots capture Bill and Ted's girlfriends, after they crash through the window, the girlfriends ask the robots: "Who are you?" and Bill goes "Well, I'm really Evil Ted!" and unzips himself and out pops Evil Ted, and the other robot goes, "And I'm really Evil Bill!" and out pops Evil Bill. When the robots are herding the girlfriends out just before knocking them out with their breath, you can see two sets of clothes in the bottom left corner if you watch closely.
Continuity mistake: Near the end of the movie, Katana and Blake are worrying about the possibility that MacLeod has spoken with Neyman and knows the exact coordinates of the hole in the shield. That's odd, because a few scenes before we see Katana and Blake monitoring MacLeod as he speaks with Neyman in the prison Max. There Neyman tells the coordinates. So they know he knows.
Continuity mistake: As Harris and Trudi are driving down the freeway, while having a shootout with other drivers, Harris hits a water container on the truck next to them and water sprays across his windscreen. In the next shot (which is wider) the windscreen is completely dry and remains that way for the rest of the scene.