Continuity mistake: If you look carefully at the monster (Frankenstein) you will see that his face is different in the ending scenes. The reason is, during the movie you see the monster take the woman doctor and throw her out the laboratory window. You then see the monster kind of stumble, which he really did and broke his ankle. So in the final scenes they replaced Lon Chaney Jr. as wolfman with a stuntman, and Lon Chaney Jr. finished the movie as the monster.
Factual error: After the first encounter with the Apaches, the covered wagon is headed to the Fort at full speed. The camera pans to the Apaches on the ridge and you can see a truck driving at the bottom right corner. (00:32:00)
Continuity mistake: The length of Edward G. Robinson's necktie rises and falls, often within the same scene.
Deliberate mistake: The same scene of William Bendix at bat swinging and missing is used repeatedly in the film.
Factual error: When the riders are watching the wagon train, in the background you can see a communication tower with conical speakers.
Revealing mistake: When the American pilots flying P-47 Thunderbolts are attacked by German fighters, the German planes are really American P-51 Mustangs painted with German markings.
Continuity mistake: In the scene where Judy Garland and Fred Astaire go to the nightclub to see Ann Miller, Ann invites Fred to come up and dance with her. When she is dancing by herself, she is wearing red high heels. When Fred comes up, she is wearing red flats.
Revealing mistake: When Howard and Curtin chase Dobbs, they pass a dead donkey which is obviously breathing, and the rope used to tie its legs together is visible too.
Continuity mistake: Near the end of the movie, Lucinda is severely injured in her leg, and has to hobble to walk. In the last scene (a short time later) as she approaches her home, she is walking with no problem, and has her arm in a sling.
Visible crew/equipment: During the movie whenever Bob Hope is pulled off the wagon by his team of horses you can see a board leaning against the wagon that was used to help the stunt man when he was pulled off the wagon.
Audio problem: When Phillip plays on the piano, the music doesn't match his finger movements.
Audio problem: In a scene when the Blandings first move into their dream house, Cary Grant (Jim Blandings) says something to a workman and his lips clearly don't match what is heard.
Continuity mistake: When Leona picks up her hand mirror, her medicine tray is positioned directly in front of her on her bed. When she puts the hand mirror down in the next shot, the medicine tray is pushed about a foot away from her bed.
Plot hole: When Ralls runs the Witch onto the reef, he is at the helm. As she strikes bow on, the wheel spins madly for no reason, as the tiller ropes would not have been affected by the collision.
Continuity mistake: When Montgomery Clift puts the boy into his jeep, the jeep has the standard seats. When he arrives at his house with the boy, the jeep has custom seats. The seats change again later in the movie also.
Continuity mistake: When Sylvester runs away from Elmer in his bedroom, he opens a door and the handle is on the right hand side. But when Elmer opens the door, the handle is now on the left.
Factual error: At the start of the film the father (Cedric Hardwicke) alights from a LNER suburban train then walks to his Wimbledon home. The film is set in 1913 but the LNER was not formed until 1923. That apart, LNER suburban services did not serve Wimbledon. A few scenes later the father and mother are sending off their son at Liverpool Street Station on his journey to Osborne Royal Naval College at Dartmouth. Strange since Dartmouth would have been (and still is) reached from Waterloo.
Continuity mistake: When Casbah looks at the picture of Daisy on his dressing table, there is some writing on the left hand side of the picture which reads "With love - Daisy." When we see a close up of Daisy in the next shot, the picture has changed, the writing has moved to the right hand side and now reads "Love Daisy."
Continuity mistake: When Sam says to Bugs, "This town ain't big enough for the two of us", Bugs is holding a carrot in his right hand. When Bugs runs out of the saloon in the next shot, the carrot he was holding has disappeared.
Continuity mistake: When we first see the baby bird in its nest at the beginning of the cartoon, you can see that the nest is positioned on a branch, but when we see the bird attempting to fly later on, the nest is now in the crook of two branches.