Revealing mistake: When Ratigan is sneaking up on Basil inside Big Ben, there is a shot where both characters have their backs to the camera. In this shot, there is a piece of equipment directly in front of the turning gear they are standing on. This piece of metal can be seen to flicker for a few moments.
Revealing mistake: When Sardo is aiming at Jarrell running you can see Kee Nang hiding behind a post, looking to the side waiting for her turn to get into the shot. (01:13:55)
Revealing mistake: When Jackie jumps on the hot air balloon, he is supposed to be REALLY high in the air. Still you can see tops of trees on the lower right corner of the screen.
Suggested correction: You should submit a screenshot of your claim because I can't see any trees to indicate the hot air balloon was low to the ground. You can see plenty of trees in the background, but they're far away and the balloon is way above them. In real life, Chan actually jumped from a plane onto an actual hot air balloon in the sky. It wouldn't make sense for it to be low to the ground because he wouldn't have time to recover by parachute if he messed up.
Suggested correction: Some mountains are extremely tall and above what a hot air balloon flies.
Revealing mistake: At Jareth's castle, in the room with the Escher stairs, Sarah sees Toby and she jumps. It's very apparent that it's a stuntwoman jumping from the ledge in the wide shot. (01:30:20)
Revealing mistake: When Lardass pukes on the guy to the left of him, he moves his head prematurely, and you can see that the vomit is coming out of a jet (hose) positioned behind his head. (00:46:30)
Revealing mistake: When the villagers of Santa Poco are making the Amigo outfits, the sewing machines are not threaded because no thread is seen in the cloth as it passes through the sewing machine needles.
Revealing mistake: When Ayla is looking at her "ugly" reflection in the lake she moves her hand down and a second later the reflection moves its hand down.
Revealing mistake: Many times during the movie, when there is a close-up of the puckmarin, tiny wires can usually be seen attached to its arms.
Revealing mistake: When Egg Shen helps the others escape by using a crossbow-and-winch device, he fires the bolt into a stone. When the bolt digs in, the stone shudders slightly (since its made of wood or plastic, and no fixed part of the floor).
Revealing mistake: When Chekhov falls on the aircraft carrier a cloud of dust flies up as if he's landed on a mat or soft cargo. When we see him on the floor it's concrete.
Revealing mistake: When Howard's running from the female bikers, Satan's Sluts, look closely at one and you can tell it's a guy in drag, one wearing a dark blond wig. (00:10:00)
Suggested correction: I was in this part of the movie, everyone in this scene (except for the duck) is female.
Revealing mistake: During "Never Say Never" Henri instructs Chantal to fly Fievel to immigration where he should be able to find his family. At one point during this shot, Henri's right wing casts no shadow on the Statue of Liberty - only an outline of the wing's shadow is visible. (00:23:25)
Revealing mistake: Vanity's stunt double is obvious as she drives the Corvette under the semi truck's trailer.
Revealing mistake: When the crocodile attacks Sue from the water, it holds on to her canteen for two shots. You can see that the animal actually holds on to a prepared version of the canteen - it is cut in half, with its lower teeth inside to hold it more "comfortably" during the pull.