Factual error: During the gun battle, Gary Cooper runs behind a building that has an air-conditioner or swamp cooler installed in a second-floor window. (01:17:30)
Other mistake: An antenna can be seen on the building above the grain warehouse.
Continuity mistake: Near the end of the film, Errol Flynn begins to sword fight with a pirate inside the cabin of the ship. Flynn backs the pirate outside onto the deck. When the scene changes to the deck, Flynn is fighting an entirely different pirate.
Continuity mistake: When Sean shows up to meet with Mary Kate and her brother he is carrying pink roses. The entire time he is in the house the roses are now red.
Continuity mistake: When Sam points his gun at Bugs at Fort Knox, he says "But I can't take any chances!" and throws away the gun. In the next shot, the gun is back in his hand again.
Factual error: Since this film serial was made in the early 1950s there are many scientific inaccuracies about the moon in it, not the least of which is that, according to the story, the moon has exactly the same gravitational pull as Earth.
Other mistake: In Gene Kelly's 'Singing in the Rain' sequence, the taps he makes do not match up with the actual movements of his feet - they are much more complicated than the steps he makes. Since one can't tap dance in wet loafers, Kelly had to do the dance in the studio, and the taps were added into the picture. He apparently got a little overzealous.
Factual error: The chairlift for the ski resort on Mount Hood is visible in the scene that pans to the right just before James Stewart is abandoned on the mountain. This ski resort was not around when the film is set.
Other mistake: During the car chase an Indian shoots an arrow that bounces off the car's license plate and comes back and hits the Indian. But a second before the arrow hits the Indian you can see him sitting on his horse with his eyes closed and a look of pain on his face as though the arrow had already hit him.
Continuity mistake: As Lana Turner and Kirk Douglas are toasting with champagne, the cigarette she is holding disappears.
Continuity mistake: In the scene where Bing Crosby is talking to Ethel Barrymore at a picnic day for the girls of he very snobbish school, he makes a big deal out of taking out a cigarette and lighting it, but in the next shot - no cigarette.
Other mistake: Before the trial by combat, when Richard Taylor and George Sanders choose their weapons, they are brought to them on their shields. But this happens to quickly, right after the choices were announced, as if predetermined.
Visible crew/equipment: When Ugolin is chasing the rabbit you can see a crewmember duck behind a bush.
Continuity mistake: When we see the dog pound proprietor sitting at his desk at the start of the cartoon, you can see the telephone has a cord attached to it. When he picks up the phone, the cord disappears.
Continuity mistake: When Poochini is rehearsing, Mysto the Magician knocks on the door of his dressing room. At this point, you can see that the handle is on the left hand side of the door, but when Poochini opens the door, he opens it from the right hand side.
Factual error: Players didn't wear numbers on uniforms at that time.
Revealing mistake: When the Prince and Princess are catapulted over the wall of the Giant's castle, you can see their shadows on the "sky" above the wall; the sky is a studio wall painted blue.
Continuity mistake: When the green devil recalls the time Tom serenaded another girl with his big bull fiddle, his whiskers disappear for a moment.
Continuity mistake: In this scene we see a flight of Navy Corsair fighters leaving the deck of an aircraft carrier on a training run. While in the air a close up shot of the flight leader's cockpit reveals that the aircraft in the background have changed into Grumman Wildcat fighters. When they make their attack run it's back to Corsair fighters with no sign of the Wildcat fighters.
Continuity mistake: The pictures on the wall of Calvero's apartment move around during the scenes, particularly the photos flanking the clock on the mantle above the fireplace. A particularly striking example is during the scene wherein Terry recovers the ability to walk. The scene starts off with a photographic-profile-portrait of Chaplin (not decked out as Calvero the Clown) on the left side of the clock and on the right side of the clock, a full-length photo of Calvero the Clown wearing a straw hat, and leaning on his cane, which is held in his left hand. As the scene progresses, the portrait to the left of the clock is replaced by a half-length photo of Calvero the Clown wearing a top hat, with his cane swung across his body, angled up. As Terry realizes she can walk, the portrait re-appears to the left of the clock, and there is nothing to the right of the clock.