Other mistake: In the Todd-OA version, just before the song "Oklahoma." Gordon MacCrae puts his hand on the porch post and the post moves off the rail. He then pulls it back.
Continuity mistake: Lady is put in her bed and the master leaves the kitchen but he goes back in and puts a newspaper on the floor and leaves again but Lady gets out of her bed so the master comes back once more and puts her back in her bed but the newspaper on the floor has vanished.
Continuity mistake: When they are on the back porch, watch the Coke bottle. The level of the liquid in the bottle goes down, then up, then down, etc.
Continuity mistake: During the robbery, the taxi driven by Danny Green changes from an Austin to a Morris Oxford and back again. Both types are the same colour, but the Austin is the one with the rounded radiator grille, and the Oxford has a flat radiator.
Factual error: The movie takes place around the time of WWI, definitely before 1923. In the carnival scene, the calliope is heard playing "Ain't She Sweet". This was the number one song ... in 1927.
Continuity mistake: During the desert chase sequence, when our hero is run off the road by Ernest B. his missing arm is momentarily transposed when he steps from the jeep.
Other mistake: The catapult on the battlements Jean uses to evict the castle guards is rather curious. First, there is neither a bow nor any torsion to 'power' the weapon, and secondly it just seems to cock itself, right after each shot. All that Jean does is pull the lever and none of her diminutive helpers stand by for any cocking work whenever the catapult arm is shown.
Continuity mistake: Sacajawea (Donna Reed) dives into the water to retrieve some important maps, which have fallen in and been taken to the back of the boat. When she dives in, the maps are back to the original area they fell into, when they should have been quite a distance from where they landed in the water.
Factual error: While the Confederate captain is explaining the mission, a couple of the "patriots" are inserting cartridges into their Colt Peacemakers. A neat trick, since the Civil War ended in 1865, and the Peacemaker wasn't introduced until 1873.
Visible crew/equipment: In the very first scene when the camera pans in to the butcher shop, you can clearly see the shadow of the cameraman on the lift.
Continuity mistake: In the scene where the Reluctant is in the port of Elysium and the men are on shore leave, a truck load of MPs show up. Ttheir patrol leader tells Mr. Roberts that his men will be stationed along the starboard side of Mr. Roberts ship for the remainder of its stay in port because of the problems various members of the ship had been causing while on shore leave. No sooner do the MPs line up along the side of the ship do you see one of the ships crew flying down the dock on a motorcycle. When the motorcycle passes the ship the MPs who just 10 seconds before were lined up along the ships starboard side are now nowhere to be seen.
Continuity mistake: When the soldiers are ambushed by the Germans, they jump off and Jack Kelly is wounded in the arm, showing a torn shirt and bloody arm. Later when Audie Murphy is wounded and in the hospital Jack Kelly visits him. The only bandage on him is on his hand, which wasn't injured before.
Factual error: When Jimmy Stewart is almost down to the runway during the bad weather, the aircraft exterior shots show the type of cloud tops found only at high altitude, not low to the ground.