Continuity mistake: In the scene where Gerald Tetley confronts Major Tetley (his father)and talks about how his father gave the order for three innocent men to be hanged. His father listens till Gerald finishes then walks to a door feeling guilty, opens it and goes inside the room. The shot is focused on the door. A shot rings out and the Major has killed himself. Meanwhile we still see the door, then it opens and within a second the shot goes back to Gerald. (01:10:10)
Continuity mistake: When John Mills is looking through the periscope whilst searching for the German battleship the side view shows him moving the periscope from right to left, but when it suddenly cuts to a shot of what he is actually seeing through it the periscope is strangely moving from left to right.
Continuity mistake: In the scene where the tank crew meet up with the weary band of soldiers, Fred Clarkson (Lloyd Bridges) has a very distinctive graze on the right side of his forehead. It seems to disappear then appear then disappear during the film. When Clarkson lies injured there is no sign of the graze - there should at least be a small mark of the graze but there is nothing.
Continuity mistake: The bandage Jane places on Tom's forehead changes its size and angle between takes. (01:10:45)
Continuity mistake: The Phantom's right eye only becomes disfigured once he's unmasked - it's normal the rest of the time.
Continuity mistake: When Spud is shown tripping over the chair knocked over by Johnny at the end of the film, his feet are shown clear of it. When the shot changes as his men arrive to help him up, his feet are suddenly completely entangled within the framework.