When Ed is sitting in the rocket talking to Alphonse Heidrich, the hair line on the back of Ed's neck changes between shots.
In one scene, an owner of a shop speaks with an officer. The uniform of the officer isn't a German uniform, it's British.
During the Putsch sequence, the shot where the NSDAP members are marching depicts some as having MG42 Machine Guns. They were not yet invented at the time the movie takes place.
The journal "Die zeit" was released since 1946, while the movie is before WW2.