Patton (1970)

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: In the beginning of the movie when the child is trying to remove the ring from a dead American soldier it is obvious that he is pulling on the finger and not the ring.

Revealing mistake: In the scene where a child is seen stealing a ring from a dead soldier's finger, the soldier's arm is visibly moving and twitching.

Revealing mistake: When Patton is inspecting the barracks at the beginning of the movie he swipes a picture of a "calendar girl" off the wall. If you look there are a number of scrapes already on the wall. There were obviously a number of retakes.