Continuity mistake: In the scene where Trevor Howard and José Ferrer are sharing what appears to be some port (about 50 minutes into the movie), the port decanter has a drip stopper in the long shot which disappears in the close-up shot of Leslie Howard and then re-appears in the following longer shot.
Continuity mistake: When the bogus male nurse with Mrs. Carroon is outside in the rain, his coat and hair are soaking wet. But when they run to the staff entrance (a few seconds later), his hair and coat are bone dry.
Continuity mistake: When Tom is running away from Uncle Pecos, he runs into the house and slams the door. When he slams the door, you can see the little door at the top has nothing on it, but in the next shot a handle has suddenly appeared.
Factual error: The system devised to get the height right was, in the film, said to have been thought of by the 617 Sqn crews following a visit to the theater. In reality it was devised by the 'boffins' at Farnborough.
Suggested correction: See many previously posted 'mistakes' of this type and the standard correction: this is not a documentary and never pretended to be. It is a war drama and many facts were changed to fit the action.
Those correction are often made in fallacy. Dramas based on historical accounts have liberty to change small or inconsequential things, like adding a person that may have never existed, or change a relationship for dramatic purposes. Despite not being a documentary, unless it's a fantasy film, changes in historical facts are mistakes (for example, a drama can't have the Eiffel Tower in London just because it's not a documentary).
Suggested correction: This was the version given in Brickhill's book. The real story wasn't published till many years after the film was made.
Character mistake: After Cal goes to the secret lab in Georgia, he and two others go into his new lab. When they enter a cat jumps up on the counter. Dr. Adams says "This is Neutron. We named him that because he's so positive." Neutrons are neutral and electrons are negative. It's protons that are positive. They should have named the cat Proton.
Continuity mistake: When Bugs discovers that Mr Hyde fired a hole in the wood that he used to board the door up to stop Mr Hyde from entering the basement, the number of planks change between shots.
Continuity mistake: Before Tom is about to draw a line on the alarm clock on the blueprint, you can see on the left hand side of the clock there is an "A" and an arrow, and on the right hand side is some writing. When Tom draws the line, the "A", arrow and writing have all disappeared.
Factual error: All the troops in the Fetterman massacre are cavalry. In fact, the majority of the detachment, including Fetterman himself, were infantry.
Continuity mistake: When Daffy asks Elmer to read out his name on the red book, you can see that he is holding the book with his hands facing him, but in the next shot he is holding the book with his thumbs in front of him.
Continuity mistake: When the man is imitating the frog to the agent in the talent agency, he is initially holding his hat, and then throws his hands up into the air. When his hands come back down, the hat has disappeared.
Continuity mistake: When Elmer opens the door to the hungry cats, you can see that there is only a handle on the door, but when one of the cats demands more money, Elmer slams the door and the handle now has a lock with it.
Deliberate mistake: Glenn Ford strikes the window in the library door with his briefcase and it instantly shatters. In reality, a blow delivered by a briefcase to a plate glass window would have produced no more than a scratch or crack.
Continuity mistake: The book the coyote is reading has "How to Tar and Feather A Road Runner - 10th Printing" on the front cover, but when we see the coyote reading the book in the next shot, the words have disappeared.
Continuity mistake: When Sam closes the door after escaping the lions, you can see there is nothing under his feet, but in the next shot a doormat has suddenly appeared.
Continuity mistake: When the mice assemble together by the cactus to decide who will get the cheese, their positions change between shots.
Other mistake: While all the business signs in downtown Osaka are properly in Japanese, the local newspaper, The Osaka Times, is printed entirely in English.
Continuity mistake: When Butch and the other cats tiptoe past Spike at the start of the cartoon, you can see that Spike's bone is next to his kennel, but when Jerry is thrown out of the house by the cats before the film begins, he lands in Spike's mouth and the bone is now next to Spike.
Factual error: When Kitchener is shown inspecting Harry's old regiment, one group of African or Egyptian troops is shown to be wearing the Pattern 1914 Infantry Equipment, not made until 1914 at the earliest. Additionally, it has the 1918 modification to have two closing straps, so is over 20 years too late for the 1894 date at that point.
Continuity mistake: When Sylvester hammers the nails over the plug to prevent Hippety Hopper and the mouse from turning off the light, the nails change position between shots.
Revealing mistake: Several shots and whole scenes throughout this film are flipped horizontally in such a blatant fashion that even the name of the ship, "Sans Souci," appears as a mirror image.