Deliberate mistake: When Jonathan and Emma are beginning to know each other, they make their way to the wood shop, where Emma picks up an "air powered tool". The tool is a staple gun, but shoots two 3" nails close to Jonathan.
Deliberate mistake: It's a humorous twist that Randy's killing is covered up by some random guys passing by with a ghetto blaster, but there was dead silence when Randy was talking earlier; not being in frame does not block soundwaves. (01:05:15)
Deliberate mistake: Some clothes were interchangeable from one character to another (or within a character over time), despite their obvious differences in sizes/body frames. Hazel, as a much heavier senior citizen, was still able to wear her "lucky" carnation pink coat that fit her 58 years earlier when she was a skinny young lady. Hazel was also able to switch coats with Margot, who had a much thinner body. The coat on Margot even looked form-fitting afterwards. Kip's tuxedo did not look too large on Griffin. (00:45:20 - 00:49:50)
Deliberate mistake: When we look toward the bar, Mrs. Robinson's calf is well below the edge of the bar. In the next classic shot of Benjamin filmed from behind the bar through Mrs. Robinson's bent leg, her calf is above the bar. (00:12:30)
Deliberate mistake: During the scene where Richard is playing croquet on the lawn in front of the Delta Iota Kappa house, the letters of the fraternity are visible on the front of the house. The Greek letter for "Delta" should be a triangle yet it is the letter "D" in the shot. This is presumably to follow the "DIK" joke that would not be as obvious if written in correct Greek letters.
Deliberate mistake: When Seth Green and Lance pull up to Ian and Felicia, the car being pulled by the carriage should roll a little bit after the carriage stops moving, but instead it stops on a dime when it is only being pulled by rope, and nothing else to stop it with when the carriage stops. (00:42:00)
Deliberate mistake: In the very first shot of Korben Dallas, his bedside clock is facing away from him, towards us. We can read it, but he shouldn't be able to because he'd be looking at it backwards.
Deliberate mistake: When Wyatt comes out of the Oriental and joins his brothers in the street to tell them he's acquired a quarter interest in a game, a herd of cattle is passing them in the street but there's no dust kicked up by the cattle, when in reality there would be a lot of dust on a dry desert street in Arizona.
Deliberate mistake: There was a black wrought iron fence behind Whitney but with enough space for JD to drive between them. After JD parked, Whitney (and her friend) were much closer to the fence, but they were also at the rear of JD's parked SUV, which would not be spatially possible. When JD, Jane, and Ally got out of the SUV, they walked right in front of Whitney, who was now much closer, and the fence was no longer behind Whitney. (00:27:50 - 00:28:14)
Deliberate mistake: Gray's rental car just happens to be the one car out of the hundreds in the parking garage that the bad guy chasing Gray and Darby crashes into, setting off the bomb he had placed.
Deliberate mistake: In the ambulance scenes, John Goodman is given oxygen via a nasal tube, probably so he could tell his story. In real life, a mask covering the nose and mouth would be used for maximum effectiveness in such a critical situation.
Deliberate mistake: As George is speeding after Jackie on his motorcycle, in some of the shots as he rides past the camera it's apparent that it is not Warren Beatty in these shots but a stunt double, unlike other shots where it is Warren on the motorcycle. (01:42:20)
Deliberate mistake: The music in the 50s wasn't, by far, the Shakira pop and hiphop style that the people dance to in the movie.
Deliberate mistake: During Alejandro and Elena's duel, he slashes her skirt and reveals her bare leg. When he slashes off her whole gown, she's somehow wearing leggings. Obviously so Catherine Zeta-Jones would not be naked.
Deliberate mistake: While Laurence is driving to the park trying to find Martha there are closeups of his car en route, and one of the closeups of the front left side of his car is a flipped shot, note the backwards "Saab" and the surface damage which is actually at the right side of his car. (00:56:00)
Deliberate mistake: To keep things simple, the movie relies on the Lancaster County Sheriff as a county police force. In reality, the county sheriff serves the county court (transporting prisoners, for example) but does not serve as a county wide police force. In PA, each city, borough, and township has its own police force. Note the varied colors of police cars at the farm in one of the final scenes. These were borrowed from the various local police forces (Lancaster City, for example, is robin egg blue with a white top).
Deliberate mistake: When Jenny writes "dick" on Matt's forehead, she does not stop the beam but the word is written with the letters separated.
Deliberate mistake: In the scene where Bob and Charlotte first glance at each other in the elevator, the film has been reversed. 3 mistakes are visible. The first one is that the woman's Kimono is reversed, left side tucked into the right. All Japanese garments are always tucked in right side first. Only on the day of your funeral is the left side tucked in first. The second mistake is the lapel hole on Bob's jacket; it is shown on his right. The lapel hole is almost always on the left side of a men's suit or sport jacket. And in every other scene in the film, his lapel hole is on his left. The third is the birthmark by the ear and the 1 inch vertical scar on Bill Murray's cheek are shown on his right side. When in actuality, they are on the left side of his face. (00:08:00 - 00:08:35)
Deliberate mistake: After trying to get away from the monster, Costello finally unties the boat as Abbott rows away from the burning dock. The next shot of the boat has Abbott slowly rowing the boat, but you can see it's not moving as there's no wake, and when they jump off the boat after the Invisible man speaks, it doesn't rock, meaning the boat was mounted to something to prevent any movement, so they could make the jumps into the water.
Deliberate mistake: When the police blitzes the "traditional English breakfast" joint, in the background the menu display advertises "Omlettes", and in the close-up on the owner you can read the word "Mashrooms." It's surely deliberate to show how the joint is not exactly ran by purebreed English people - although it should be noticed that there is an inconsistency with previous scenes when the board was different, and even the word "Mushrooms", handwritten, was spelt correctly. (01:23:00)