Other mistake: In the opening scene, as Captain Glenn Ford is watching a Japanese freighter travel right to left through his submarine's periscope, the freighter is actually going backwards. The bow of the ship is on the right, not the left, as it should be.
Continuity mistake: When Quinlan is with Joe Grandi at the bar, Quinlan breaks his sobriety while seated at a round table, but in the last overhead shot the table is rectangular. (00:57:00 - 00:58:25)
Other mistake: During training, when the men are running and the two British men come out of the bushes then shoot at the ground, there are 3 rows of bullets going past but only 2 guns being fired.
Continuity mistake: In the scene towards the beginning where pair- chained interracial prison escapees Noah Cullen and Joe Jackson (Sidney Poitier and Tony Curtis) are trying to cross a river together without killing each other, they get carried away downstream and are stopped by a tree. The mistake is, Sidney Poitier's bald headed stunt double is noticeable losing control while floating downstream, visibly and audibly crashing head first into the tree. He is briefly flailing and struggling from the unexpected impact until Sidney Poitier reappears properly floating towards the tree without struggle. This mistake is less than 30 seconds and is awesomely noticeable best on Blu-Ray disc. The shot of Tony pulling Sidney out of the river concludes the scene.
Factual error: The movie's title "The Inn Of The Sixth Happiness" is the name of the mission station that Gladys Aylward/Ingrid Bergman sets up. In reality this was called "The Inn Of The Eighth Happiness." Numerology is popular in China, where eight is regarded as a particularly auspicious number. Apparently the film company thought "sixth" had a better ring to it than "eighth." In the movie it is explained that there are six levels of happiness. This is not a Chinese belief and seems to have been invented for the movie.
Other mistake: Outlaws are chased by a mounted posse. One outlaw up on a hill shoots two of the posse members from long distance. Next shot, the two injured posse members are lying on stretchers and the chief deputy orders someone to go back to town and get a wagon. The stretchers were canvas, wooden handled, military style. Where did they come from?
Continuity mistake: The sheriff's wagon the 30-foot man picks up is a 1958 Plymouth. But the car that is rolling after he drops it lands on the ground is a 1950s Chevrolet. When the sheriff tries to call for help, the smashed car is the 1958 Plymouth again.
Continuity mistake: When Diestl and Hardenburg attempt their wild dash to the coast on the motorcycle, they pass the same wrecked Kubelwagen three times.
Continuity mistake: When King Arthur says "A good idea, fool!", Bugs Bunny stops and you can see that behind him is a wall. In the next shot, Bugs is now in front of King's Arthur's chair, and when he says "Beheaded?" he is back in front of the wall again.
Continuity mistake: When Daffy rushes up to take his breakfast from Elmer, you can see the door behind them is closed, but when Elmer tells Daffy he's had enough, the door is now open.
Continuity mistake: Ben kicks the tractor when he can't get it started, denting the grille, the next time we see the tractor the grille is straight.
Continuity mistake: David Hackett is talking business organizing ranch business while his brother Ed is leaning on the counter, gawking at the beautiful Clee and passing her cloth. He has his right arm up in the close-ups, but the left arm up in the wider shots. (00:04:55)
Continuity mistake: When the Bayonet is thrown at Strong, it is thrown with the butt of the rifle facing left, but is caught with the butt facing right. (00:41:00)
Revealing mistake: When a yellow cab pulls up to the curb, it is obvious that the street is part of a studio backlot and not a real city street because the businesses have no names. The sign outside one building says simply "Tobacco." The diner has only the word "Restaurant" painted on its windows. Another business has no identification other than "Fish and Poultry" painted on its window.
Factual error: The film begins in 1860, but the majority takes place 20 years later, so 1880. When James Rankin obtains files on the Haymarket Strangler/Edward Styles case we are shown another box labelled with details about Jack the Ripper, who wasn't active until 1888.
Continuity mistake: When Daffy is standing on the branch of the tree ready to jump off, he is holding on to a rope. When the camera angle changes to behind Daffy in the next shot, the rope is missing.
Factual error: You can't expect a great deal of historical accuracy from a movie that narrates a love story, conveniently ignoring the glaring fact that one of the two lovers was DEAF. Nevertheless, here Francisco Jose de Goya paints for his lover, Duchess Maria, a 1797 painting, "The Black Duchess", only after he already painted "Charles IV of Spain and His Family", finished in 1801, and the St. Anthony of La Florida frescos, 1798.
Revealing mistake: In the opening credits, Richard Widmark is driving a car with Doris Day in the passenger seat. Widmark does not turn the steering wheel, even though the rear-screen projection shows him going around a curve.
Audio problem: When Bugs says "I just hope I will be in one piece, so I can appreciate it", his mouth is not moving.
Revealing mistake: Whenever our heroes are shown firing the Vickers guns on or off the vehicles, they are very obviously fitted with blank-fire adapters to the front. The belts of ammunition for them throughout the film are also blanks - the cases are visible, but the bullets that should project out the other side of the belt are not present.