Revealing mistake: In this scene we see Cheetah jumping down from a tree to the ground. In the next shot we see Cheetah and a circle of light moves, which indicates they were using a mirror or even a light for extra lighting to brighten up the shot. This happens very briefly and is very noticeable.
Revealing mistake: In this scene we see Claudette Colbert and her husband talking. In the background it's obvious the ocean scene is a stage prop, the waves in the sea don't move at all.
Revealing mistake: Early in the movie, there is a visible circular, plastic looking effect on Gideon's arm as he removes the bullet with the knife. This is more noticeable around his shoulder when he cauterizes his wound with the hot knife.
Revealing mistake: During the opening credits, as a crab descends past the periscope, the string attached to the crab is visible.
Revealing mistake: Technical Glitch: In the opening scene before the opening credits. The British are being run out of one of the last remaining fields in France. The Sergeant is burning the "lame ducks" when German planes attack. A German plane attacks almost directly toward the camera, you hear machine gun noises but no effects. Next a plane attacks from right to left, you hear machine gun noises and see the effects indicating the bullets striking the target. After the second plane has gone you see the effects of the first planes attack.
Revealing mistake: In the scene where Lt Stachel and an ordinary soldier search for the wreckage of Stachel's unconfirmed first shoot-down, it is supposed to be dark and pouring rain but blue sky is seen in the background.
Revealing mistake: When the Marines shoot the Japanese pilot, you can see the wire used to set off the blood bags coming out of his pants leg as he falls. (01:11:30)
Revealing mistake: There is a short section where a U.S. soldier hops a rugged looking stone wall in France. As he goes over the wall, it moves back and forth a bit as if made of styrofoam and wood.
Revealing mistake: When the tank/truck driven by Marvin is crossing the stone bridge at the end, they are met by a small German gun vehicle, which they run off of the bridge. The camera angle changes to below the bridge and you see the German vehicle fall from the side of the bridge into the water below. If you look at the bridge material that shatters you can see pieces of wood and hollow areas where obviously it's not real stone. (02:25:00 - 02:30:00)
Revealing mistake: When the platoon hear the church bells, they mistake it for the invasion signal and construct a barricade across the high street. If you look behind them you can see cars parked on the road in the distance that date from well after the 1940s.
Revealing mistake: John Wayne suffers a broken arm and goes for a x-ray wearing a cast. At the bottom of the cast a slit is visible which allows the fake cast to be easily removed.
Revealing mistake: When they find the paper map sticking out the Iraqi soldier's bottom it is neatly rolled up and straight. One should imagine it being quite crumpled after having spent some time in this particular hiding place. (00:08:00)
Revealing mistake: The British intelligence officer Wells, who is being trained to infiltrate the Gestapo headquarters at Lyon, would never pass as a German because of his slight but still quite noticable accent. (00:47:45)
Revealing mistake: If you pay close attention to the close up shots of Doug's F-16 dropping bombs or launching mavericks, you will notice that the fighter is a poorly detailed scale model of the real thing. In the scene where Doug drops the Hades, you will notice that he is actually a barely painted figurine and that he suddenly has no headrest/ejection chair.
Revealing mistake: The shot in the station is somewhat revealing, not only a modern diesel train (as already reported) in 1914 but also a third electric rail. (01:05:15)
Revealing mistake: In the opening scene as the characters play a game of hurling, a farm is visible in the background, at the foot of the mountain. The farm buildings near the farmhouse are much too large and modern to have been constructed in 1920's Ireland.
Revealing mistake: In the opening sequence when Colonel Ryan's plane has crashed and is on fire, you can see a metal pole supporting a burning aircraft shell, not a real plane.
Revealing mistake: When Guido tries to escape camouflaged as a woman and is stopped by the guards the second from right prisoner cannot help laughing. (01:50:10)
Revealing mistake: The B17 that crash lands in the beginning appears quite realistic, until during a head on shot when you can see daylight through the clear nose from a window in the back of the plane. This shows it to be model as in the real plane bulkheads would block this from happening.
Revealing mistake: In the beginning of the movie, when Jakob is chasing the newspaper, there are several times you can see the string they use to drag it.