Plot hole: Radl and Steiner discuss the entire scheme to kidnap Churchill on the Alderney docks - in full view and hearing of a number of civilians (who shouldn't be there, pace another posting), including fishermen who could might be able to communicate with the mainland. Why would they be so stupid as to discuss a top secret military mission in public? In reality, they wouldn't even discuss it in front of their own men.
Plot hole: When the general approaches Steiner in the train yard, he says 'you didn't seem so discriminating a moment ago' implying that he saw Steiner help the Jewish girl onto the train. But this is impossible, as there was a moving train between himself and Steiner when the incident happened. For all he knew Steiner could be blameless.