Best war movie mistakes of 1969
Continuity mistake: It is 1940. Two pilots come out of a house - one of them has just lost his wife and family in the London Blitz, the other is an RAF Squadron Leader. The door they come out of has a modern electric bell push - a post 1965 version, white rectangular box with a round button.
Revealing mistake: When the Remagen bridge is bombed, it is obvious that the bomber planes shown have been taken from several shots (possibly also from an earlier film) and the shots were superimposed. Also, the bombers appear transparent, and the background sky's color is unnaturally strong, too.