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.
Revealing mistake: This film has the old movie trait of Nazis having German accents rather than actually speaking in German, which is fair enough as they take up the majority of the screen time. However, not everyone adheres to this rule and there are many characters, minor and major who slip in and out of accents, and many never have them at all.
Add timeDavid Mercier
Continuity mistake: When Steiner lifts up the Jewish girl, if you look closely, you can see the rear end of the train about 20 metres away. Yet somehow Steiner has time to ask her name, wish her good luck, set her down on one of the carriages and watch her get shot before the train fully passes him. The departing train also conveniently slows down for him to drop the girl.
Factual error: When Michael Caine is standing outside the village church, it is clearly visible that double yellow line road markings have been blacked out (covered up). The film is set during the war, but double yellow lines did not make an appearance in the UK until 1958, therefore it is clear that the filmakers blacked them out to avoid an anachronism.
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.
Continuity mistake: After Donald Sutherland parachutes into England, he walks across a cow paddock towards a gate. As he climbs over the gate, you can see there are no cows to the left of him along the fence but in the very next shot, you can see a line of cows along the fence which weren't there in the previous shot.