Revealing mistake: Several maps of Europe shown in the film have Germany divided into East and West, and show national borders from 1945 onwards.
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: 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: At the very end, a bat flying out of the mist toward the camera was intended to imply that Barnabas had taken bat form and could thus be around for a sequel. But through the haze, Barnabas can still be seen lying on the floor when the bat flies past. (01:36:25)
Revealing mistake: The wires holding up Jacob Marley's floating lock box and chains are visible. (00:32:10)
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: 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 Ursus is giving his speech in the Ape city, many of the Chimpanzees and Orang-utans are wearing incredibly fake-looking masks. (00:17:15 - 00:19:50)
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: After the flashback where the police investigator tells Augusta he could murder her, and she asks him who'd solve the crime, it cuts to a man outside a store window looking into the store, whilst the investigator watches him from across the street. When this happens, two extras walk into the shot, and the extra wearing glasses can be seen looking at the camera when he walks by. (01:07:55)