Revealing mistake: When they get back from Bunyans and the garbage is on the floor, Chet runs to the bathroom. The family and Roman follow him, you see Dan do a 3 count for everyone to run back In screaming, the blocking of that shot included a gap that you could see them off camera right.
Visible crew/equipment: In the scene of Ram and Kurt's funeral, you can see Ram's supposedly lifeless body breathing.
Factual error: When Frank knocks out the Umpire and begins to change into his clothes, the umpire is wearing white underwear. All umpires wear black in case the seat of their pants rip so the game can continue.
Plot hole: Shortly after the robbery, Kevin Kline and Jamie Lee Curtis get together in a little flat and Kline calls the police from a landline to tell them who committed the robbery. In England this would immediately lead the police to the flat from which the call was made, and the person reporting the robbery would be the first person the police would want to find and speak to. Otto has handed it to them on a plate. (00:12:29)
Plot hole: At the end of the film Mardukas reveals that he has been wearing a body belt packed with cash - "in the neighbourhood of three hundred thousand dollars" - ever since Jack detained him in New York. Are we to assume that Jack Walsh, an experienced, hard-bitten ex-police officer, now a bounty hunter who routinely chases down violent and armed bail absconders who would kill him without a second thought, didn't even perform a perfunctory search of Mardukas when he detained him? This man used to work for the Mafia! What if he was carrying a weapon? A body belt with three hundred one thousand dollar bills in it would be uncovered by even the most casual pat down.
Suggested correction: He was using $1000 bills. That's 300 bills in the belt which spread evenly absolutely could have been missed near his waist as part of his clothing.
Rubbish. I specified $1,000 bills as that would be the smallest package he could have secreted about his person, and it would still be instantly detectable. If he used $100 bills the package would be ten times larger, and he would have to carry a rucksack under his shirt.
Revealing mistake: While Akeem is getting his hair cut, you can see the reflection of the white character he plays in the mirror. It is quite obviously a stand-in, with a fatter face and different glasses. (00:33:45)
Factual error: The picture of Eddie and Teddy on the road with dad, supposedly taken in 1906, shows a Ringling Bros and Barnum & Bailey circus poster. In 1906, the Ringling Brothers circus and the Barnum & Bailey circus were two separate circuses playing in different parts of the country. They did not combine the two shows until 1919. (00:27:00)
Revealing mistake: When they are at the Nutmar camp in the mountains, Val Kilmer tells Willow "Get on that shield!" but when they go over a 6, 7, 8 foot drop when they are sledding down the snow, you can clearly see runners on the shield.
Other mistake: When Brian takes a picture of his friend Doug on the boat, the picture shows Doug in a different position than that of when the picture was taken. (01:21:30)
Continuity mistake: There is a scene where Arnie and Danny DeVito are in the washroom of a nightclub. In one shot there is a beer bottle on top of a paper towel dispenser, and in the next shot it's on the other paper towel dispenser. (01:11:15)
Continuity mistake: Throughout the film Elvira wears her trademark black dress, split to the top of her thigh, and underneath it she always wears black pantyhose. Inexplicably, this changes to black stockings and suspenders when she is undressing for bed on her first night in her new house. (00:31:35)
Continuity mistake: During the horse and buggy ride to the church through downtown New York, when one of the girls is holding the reins by herself, you can tell there is a person under a red blanket at her feet (I guess to protect her while filming in case something goes wrong,) and only a moment later, the same blanket is black.
Continuity mistake: During the "Why Should I Worry" song, Dodger goes with his "scarf" of sausages through a basin full of wet cement. Logically the cement should be stuck on the sausages, though that does not appear to happen, even though the sausages went through the cement. There is cement on his paws, though, that he needs to wash off.
Continuity mistake: In a bus scene Crash is shown holding a guitar talking about being in the majors. In one scene he's just holding the guitar, the next he has a pair of sunglasses in his hand while holding the guitar. The next scene the sunglasses are gone. A couple of shots later the guitar is sitting in the seat next to him. When Laloosh challenges Crash to a fight, he's holding the guitar again.
Continuity mistake: When mom finds the failed test in Les's pocket, it is folded into eighths. Later, when dad shows the failed test to Les, it has only been folded into thirds.
Continuity mistake: When Otho is going through the house suggesting changes he is wearing white sneakers in one room and red ones in the next. (00:16:25)
Revealing mistake: When Charlie and Daisy get the flat and have to hitch-hike, and Daisy takes off her shoes to run to the car that has stopped, the bottoms of her feet are already filthy (presumably from having to do the scene over and over).
Audio problem: When Corny introduces himself at the auto show, the audio is not in sync with his lips.
Continuity mistake: When the bad guys are outside the hotel in the convertible, they spot Lassard and one of them spits milkshake over the inside of the windshield. The milkshake disappears in the next shot.
Continuity mistake: In the scene where Tom Hanks goes back to his mother's house when he's "BIG", he tries to convince his mother it's him by telling her his birthday: November 3rd. However, in the scene (with John Heard and Elizabeth Perkins) showing the milk carton of Tom Hanks "missing" as a young boy, his d.o.b. is shown as 1/20/75. (00:16:50 - 00:53:05)