Other mistake: During the final shootout in the saloon, young Joey yells, "Shane, look out!" Alan Ladd whirls around and his gun goes off. But the gun isn't pointed anywhere near the bad guy who is standing on the second floor balcony. Shane more than likely shot the furnace that was off to the right. Yet, the bad guy still manages to do a face plant on the barroom floor.
Continuity mistake: After the two children walk away after dropping their ice cream on the zebra crossing all trace off the ice cream has disappeared from the road.
Continuity mistake: When Audrey eats her gelato on the steps of the Spanish Plaza, if you look closely, the time is about 12:00 when she buys the cone. However, when she starts eating it, you can see that it's past 3:00.
Factual error: When Lt. Dunbar is being interrogated in the Commandant's office you can see a map on the far wall. It is a map of Germany dictated by the Treaty of Versailles which ended World War I because it shows E. Prussia separated from Germany and does not include the annexation of Austria and Czechoslovakia. These annexations were completed before the start of World War II in '39 and certainly before late '44, early '45 when the film took place. It is highly unlikely any German officer would have this map displayed not only because it's inaccurate but because it displayed the territorial losses brought on by the humiliating defeat of World War I.
Visible crew/equipment: Opening credits (also a few minutes in) has a fiery spaceship crashing into the camera for this was a 3D movie. What's interesting is that a mirror can be seen on the left portion of the screen just before the collision. This was apparent at the theatres and on the VHS tape release. For some reason, the DVD release has it cropped out and now the spaceship is off-centered at the beginning (fortunately the bonus material still shows it). (00:00:20 - 00:03:50)
Continuity mistake: There is genuine wartime footage of Spitfires of the the right type for the period, but other scenes have later (maybe even postwar) versions flying about.
Visible crew/equipment: When the long, long trailer drives by, on its way up the steep, steep mountain, you can easily seen a camera man reflected in the trailer. (00:40:22)
Continuity mistake: When Francis Fryer throws the cowboy he loses the scarf in his hand but when the camera angle changes he has it again.
Factual error: After they bury Jack's father, the stage driver hands Jack what he refers to as a "Navy" Colt. However, in 1841, the only colt handguns were a handful of Paterson revolvers, usually carried by Texas Rangers, and in fact, the revolver handed to the boy was a cartridge weapon.
Factual error: Jane Russell and others say several times that they are sailing from New York to Paris. They might have been sailing to Cherbourg or Le Havre, but they couldn't have been sailing to Paris. The producer seems to assume that if they referred to Le Havre or Cherbourg, viewers wouldn't be able to sort it out.
Continuity mistake: While the close-ups showed heavy ice build-up on the doomed plane, the long shots showed no ice at all.
Continuity mistake: When El Khobar is romancing Margot, he keeps his face covered with a veil so she won't recognize him as her professor. As Margot is approaching him while they are singing the desert song, he pulls they veil over his face and you can see the tan lines of a wedding ring.
Continuity mistake: On the marquee that advertises the show "Band Wagon", the name of the actress is listed as Gabrielle "Girard", but when the scene switches to a shot of someone holding the program for the show, her name on several pages of the program is spelled Gabirelle "Gerard".
Continuity mistake: When the Beast first tears down the streets of New York, a lone police officer empties his service revolver at the beast before being eaten. A few minutes later, a group of a half dozen police officers pump their shotguns before firing at the beast - the officer who was already eaten after firing his revolver can be seen alive in the far left of the screen as one of the officers readying his shotgun.