Continuity mistake: When the German NCO begins to walk up the sand dune he has a stick grenade in his right boot. Next shot half way up the dune, the grenade has changed boots.
Continuity mistake: At the concentration camp, Mark Hamill opens an incinerator door, several doors along the row, and repeatedly shoots the German hiding inside. As we are looking out from inside the incinerator Lee Marvin appears behind him and says "I think you got him". The shot changes to a wide view outside but they are now looking in a different door - one of the first ones in the row.