When Bernard and Miss Bianca are awaiting Orville, Miss Bianca first takes off her coat. After she shouts, "Look! Look, there he is!" and we see her through the window, her coat has reappeared, and then it vanishes again.
Penny's teddy bear disappears after she shows off the damage to her underwear. In that shot, she is holding Teddy in her left hand, but in the next shot of Penny Teddy is gone.
Miss Bianca's handbag appears only when the two mice need something from it. It first appears out of nowhere after the mice ride the escalator at the heliport.
When Penny meets the mice, she shows them that the alligators have ripped part of her underwear. However, there was no visible rip when she pulled her nightgown over her head moments earlier.
After Brutus and Nero, the alligators, have brought Penny back to the riverboat after she tries to escape, we see Nero walking after Mr. Snoops after he's offended them. Nero is holding Teddy in his mouth, but in the next shot Teddy is in Penny's arms.
During the Rescue Aid Society meeting, one of the name plates says 'Africa'. Africa is a continent, not a country, and as such would not have a UN delegate.
The traffic light that changes (and Orville flies through) has the three standard lenses for the green, yellow, and red phases. However, in typical cartoon fashion, the light goes from green to red without any yellow phase.
The bats in Louisiana are nocturnal, but they are shown to be sleeping when Evinrude first encounters them.
The pronunciation of Evinrude's name alternates between the correct (EV-un-rude) and the incorrect (EE-vun-rude).
Medusa's car that she drives while leaving her namesake pawn shop is a Bugatti Type 40 manufactured from the late 1920s until 1930, and starts its engine with an ignition key. It should instead start up using the crank handle at the very front as the key ignition systems when used for cars was not invented until the very late 1940s.
However, it is possible she could have had the car modified with a modern ignition system. After all, she managed to have a Model T rigged into a motorboat, so customizing automobiles is something she is familiar with.
However, it is possible she could have had the car modified with a modern ignition system. After all, she managed to have a Model T rigged into a motorboat, so customizing automobiles is something she is familiar with.
The Rescue Aid Society has a delegate from Latvia. At the time the film was made, Latvia would've still been part of the Soviet Union and so wouldn't have had a separate delegate. However, when the film takes place is actually somewhat ambiguous, featuring a mishmash of vehicles, clothing, hairstyles and other things from many time periods. (Although as the film features the United Nations, it has to be set after World War II and Latvia was part of the Soviet Union then.)
When Penny shows the mice that her underwear is torn she says 'Look what they did to my pants'. Being American, 'pants' to her would mean trousers.
Or maybe she meant it as short for 'underpants', as she just didn't want to say the whole word. Like when going swimming, sometimes people just say "I'm going to put on my suit" instead of using "swim suit."
In Madame Medusa's pawn shop, the sign on the wall states "Loan Money 1/2 Rates on Diamond's". In this context, "Diamonds" is a plural, not a possessive noun, and therefore does not require an apostrophe. However, it's not uncommon in films for villains to not be particularly intelligent as a means of comedic effect (we see Jasper and Horace misspell 'electric' in 101 Dalmatians), so this error may simply be a feature of Medusa's character.
Ellie Mae's ear turns white in one frame during one of the Swamp Folk's meetings.
During the first mouse shoot-out scene (the one with the organ), Medusa falls down, and for a split second the whites of her eyes are red, and the irises are white.
During the song "Rescue Aid Society", the shadows of the mice on the band are not aligned with the characters.
At the beginning of the movie, in the shot before Penny drops her message for help in the bottle into the water, she does not cast a shadow on the lighted riverboat deck.
When Medusa drives out of the parking garage of her Pawn Shop, smoke appears before she pulls out as if she were backing up, but her car faces forward as she exits.
The Rescue Aid Society has a delegate from Germany, but at the time that this film was made Germany was still divided into East and West Germany.
When the Rescue Aid Society delegates say "Hear hear", the subtitles on the DVD incorrectly spell it "Here here."
On the YouTube Movies & TV, Google TV, and Prime Video digital versions, around the 4:17 mark, the title "United Nations New York" does not present itself.
At the meeting of the Rescue Aid Society we see a delegate from Austria. Not long after we see another delegate from Vienna. Vienna, of course, is the capital of Austria. If the Rescue Aid Society is like the United Nations, then all delegates should represent nations, not cities. More importantly, even if cities were represented, it would make no sense to have two delegates from the same country.
The Rescue Aid Society has a delegate from Arabia, which is a peninsula containing several countries, not a country in its own right.
Given its size, there's no way the diamond could have just randomly ended up inside of the skull.
Bernard carefully counts the steps of the runway stairs and is perturbed when the number comes to 13, but he actually completely ignored the step between those he counts as his 11th and 12th.
Bernard rashly decides to get to the other side of the hole by edging along its perimeter, but it would have been much safer if he had simply asked Penny to throw him across. However, doing so could have left him stranded on the other side, requiring him to verify whether it was possible to cross on foot.