Factual error: When Col Steiner is imitating the American's voice over the radio he uses the words "Delta-1" or similar. Delta is part of the NATO phonetic alphabet which wasn't introduced until 1956, well after the war had ended. "Dog" would have been the correct word to use.
Continuity mistake: In the scene where Devlin is thrown through the pub window, his coat shows no sign of the alcohol which was poured over him.