Revealing mistake: Utility poles are visible in the scene of the Japanese aircraft carrier launching planes for the first attack on Midway.
Revealing mistake: When Sue Snell wakes from her nightmare, listen carefully as her mother comforts her. At one point, she calls her Amy, which is the actress's real name (they're mother and daughter in real life).
Suggested correction: Sue's mom just keeps repeating it's all right, you never hear any name mentioned.
That's because the music is supposed to drown out any dialogue.
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.
Revealing mistake: When Francis emerges from the cave, he stands in the foreground, with the distant mountains and sun in the background. The sun creates a lens flare, which is an internal reflection within the camera lens. Yet Francis is in front of the flare. This shows that the actor was composited with the background via a traveling matte process.
Revealing mistake: Navarro is climbing on the outside of the train, the overhead shot shows very wide gaps between the plates welded to the windows. When the shot changes to a side-on view, the gaps are considerably smaller. This is seen several times throughout the quick scene changes. (01:47:00 - 01:49:30)
Revealing mistake: When De Niro gets shot in the neck, his bald skin cap wrinkles considerably when he presses the wound with his hand. Confirmed by make-up artist Dick Smith in the making-of documentary. (01:40:00)
Revealing mistake: In the closing scene, you can see the modern curb & sidewalk have been covered with dirt.
Revealing mistake: When the armed gang abduct the Mayor, a LAW rocket is fired at a Lorry, the few seconds are obviously several shots pieced together. The giveaway being the driver is a dummy as the driver has no face, even after the explosion, the faceless dummy just falls out of the cab.
Revealing mistake: Following their escape from the comancheros, the two wheeled wagon driven by the old woman had a set of reins coming through the slats beneath the seat indicating that the old lady held fake reins and the wagon/horses were controlled by someone inside. Later, when they left the small town and headed to her son's ranch, a little window had been cut out of the slats where the control reins came through, no doubt to improve visibility and horse control.
Revealing mistake: When Babe is hiding in the bathroom and his attackers are prising the door off the hinges, you can see the wall move as well as the door, so showing that it's a set rather than an apartment.
Revealing mistake: When the supervisor is telling Geronimo to clean up the dog feces, there are three men across the street in front of Al's Coffee Shop watching the filming. (00:42:55)