Revealing mistake: Near the end of the film, there is a football game played between the rival MASH units. Although the game is supposed to be taking place in a remote location of Korea in 1951, late model 1960's automobiles can be seen driving on a nearby highway as the game progresses. This gave away the fact that the football scenes were shot at a university in Southern California.
Revealing mistake: When Madame gets off the carriage, Frou-Frou winnies to get her attention. Madame then proceeds to feed her. Frou-Frou eats from her hand. However, if you look closely at Madame's hand, it is empty. (00:03:05)
Revealing mistake: The cannons shown are firing blank charges, which produce no recoil. Recoil has been simulated by towing the guns backwards when they fire. The problem is, there is always a distinct delay between the discharge and the "recoil." The cannon also seem to largely fire explosive shells. At no point do we actually see a cannon ball rolling or bouncing along the ground or into any group of soldiers.
Revealing mistake: When the 3 children are waiting for their mother, the rain is pouring down. Yet, when they are gathered around the Russian guy on the floor, their clothes are dry.
Revealing mistake: When the mayor's wife attempts suicide by stuffing herself with pills, she is lying behind a sofa, only her arm and the pill bottle being visible as she pours the contents into her mouth. In the next shot (a close-up), however, the crown of her head is visible, and it is evident that she pours the pills over the top of her head.
Revealing mistake: During the Little Bighorn massacre one of Custer's lieutenants turns to address Custer and is struck in the back with an arrow, and the thick pad or board is visible under the actor's shirt.
Revealing mistake: When Brewster is flying around in the Astro-Dome at the end of the movie, in a close up you can see the cables attached to him for a good second or so.
Revealing mistake: A Nineteenth century social occasion is taking place at a mansion in the evening. The lead female vampires servant arrives by horse in front of the mansion and in the background you can see some modern tennis courts with metal gates and fences. The nets have been removed but the appearance of the courts can still be seen. (00:10:35)
Revealing mistake: In the beginning of the movie, as the couple are driving to the airport, they pass two cars, which are parked together along the side of the road. The drivers are both standing beside their cars and obviously observing and taking pictures of the action / actors as they pass by.
Revealing mistake: When the car enters the scene near the beginning of the movie where everyone is getting of the stuck aircraft, you can see the tire track in the snow where the vehicle is going to go. (00:07:50)
Revealing mistake: Whenever Stupid Bat is flying, the wires pulling him up are visible.