Continuity mistake: When Schaffer climbs the rope into the castle, he reaches the top of the rope, grabs the window sill and starts to pull himself in. It then cuts to inside the room where Schaffer can be seen outside holding on to the top of the rope and then grabs the window sill to pull himself in, again.
Continuity mistake: During this sequence at the radio transmitter in Admiral Rolland's headquarters, whilst the Admiral is attempting to regain contact with Smith, Colonel Turner is seen in the background, smoking. At the beginning of the sequence, one shot shows him holding a cigarette between the fingers of his right hand. After a cut back to the Admiral, the next shot shows Turner holding the cigarette in the fingers of his left hand. (00:53:10)
Continuity mistake: As the stolen bus ploughs through the German airfield Smith yells to Schaffer, "Take out the control tower," so Schaffer and Mary point their guns high and start firing. There is a long shot of bullets strafing the control tower, glass shattering and the traffic controller falling backwards as he is hit. It is followed by a quick close-up of him in perfect health, shouting into his radio, then being mowed down by the stream of bullets. (02:20:00)
Continuity mistake: When Major Smith and the others have completed their parachute jump, they find Sgt. Harod dead in the snow. Major Smith says at first Harod broke his neck on landing, but later said to his trusted comrades Harod was murdered after landing. Since he was murdered by a member of the landing party there would be tell-tale footprints of the murderer in the virgin snow around Harod's body, but there are no footprints around him at all.
Continuity mistake: In her castle room, Mary lays all the sticks of dynamite on their sides in the suitcase. When Smith opens the suitcase in the meeting room after they got the names of the spies, the dynamite is now standing on end.
Continuity mistake: When Smith fires at the last German Kübelwagen chasing his team on the Oberhausen airfield runway, the scene alternates between two perspectives of Smith firing from the bus's engine cover: One from the front, the other from his backside. In each of these alternating shots, Smith holds the front part of his MP40 in a different grip. (02:20:55)
Continuity mistake: After the explosions start in the castle, three SS soldiers knock on the door of the room where the General, Colonel Kramer and the guard are lying dead on the floor. The General can be identified by the red stripe on his trousers and the guard is on the right facing away from the camera but the body in the centre that is supposed to be Colonel Kramer looks nothing like him. The face is different, and he has swept-back blond hair, whereas Kramer's was much shorter and greyer. It's a very short scene, so they probably got members of the film crew to pose on the floor rather than the actors themselves. (01:52:31)
Continuity mistake: It may not be a mistake but early on in the film when Smith and company are preparing to jump from the aircraft, the jump master removes the fuselage door completely and sets it aside. The same aircraft returns at the end of the film to collect them but when Colonel Turner opens that same door to jump to his death, the door is now firmly held in place by hinges. I say it may not be a mistake because some doors lift off their hinges but I can't see why the jump master would do that mid-flight as there is a hell of a slipstream and the door could easily be lost. (00:08:08 - 02:26:49)
Continuity mistake: The camera is looking down on Smith as he climbs up the rope and there are no footprints in the snow on the roof of the cable car room below him. The camera then cuts away to different angles but when we see the same shot of Smith a few seconds later there are clear heavy foot prints in the snow on the roof. (01:09:40 - 01:10:10)
Continuity mistake: When Eastwood gets off the German motorbike after the escape from the town, the seat of his trousers are wet but 2 seconds later are bone dry.