The Heroes of Telemark (1965)

Plot hole: When Knut and Rolf are setting the bombs in the engine room of the Hydro ferry, they are interrupted by a German soldier who they quickly overpower and kill. Why don't the Germans then notice that this soldier is missing? The clocks attached to the bombs show the time around 01:35am when the soldier is killed yet the alarm still hasn't been raised when Rolf catches the ferry several hours later at 9am. This is far too long for any soldier to be on sentry duty without reporting in to the Guardroom. The Germans would have known that the soldier was on duty on the ferry and when he didn't report in then they would have searched the boat thoroughly and found the bombs. (01:51:30)