Continuity mistake: When the Nazi SS guard puts a pistol to Rutger Hauer's head, it's a Luger, but when the guard turns around, he's holding a Walther P38.
Continuity mistake: The prison camp is surrounded by a mine field. Oddly enough, the grass on that mine field is perfectly trimmed. I would love to see someone mowing the mine field.
Factual error: Some of the SS rank insignia is incorrect. Most of them do wear correct insignia, with two exceptions. Wagner, who is addressed as Hauptscharführer, actually wears the collar and epaulette insignia of the next higher rank of Sturmscharführer. In reality, Wagner held the lower rank of Oberscharführer. Frenzel is addressed using his correct rank of Oberscharführer, but oddly wears the collar patches of the lower rank of Scharführer and the epaulettes of the higher rank of Hauptscharführer. Bauer and Beckmann, on the other hand, wear the correct collar patches and epaulettes for the rank of Oberscharführer which they did hold.