Factual error: When the humans are capturing the gorillas, Clayton fires about 15 rounds from his double rifle. This is pretty impressive, considering this is the early 1900's.
Factual error: If the access hatch to the nose wheel well on an airliner was opened at any time during the take off run every alarm panel in the cockpit would light up like a Christmas tree. The pilot would immediately abort take off.
Factual error: In the opening short "Pikachu's Rescue Adventure," in the Bellossom song and dance shot, a Poliwhirl calls itself a Poliwrath. This is obviously a mistake because of the body differences between the Pokémon.
Factual error: When the police arrive at the Little house to take the "missing person" report, their car has a blue light on top. Police in New York display red lights.
Factual error: In the scene where the Iron Giant is spinning the boy around in a junk car he is holding, notice that the car resembles a 1959 Cadillac...however since the film is set around 1957, this is not a likely car to be found anywhere yet, much less a junk yard. (00:46:20)
Factual error: The TV station in the movie is KGSC channel 10, and the building shown at the beginning for the exterior shots is in fact Santa Barbara's TV station, but it's channel 3 and its call sign is KEYT. There is no channel 10 in Santa Barbara. In fact, the only channel 10 in Southern California is in San Diego. (00:01:45 - 00:34:45)
Factual error: When the gang follows Ben Ravencrift home, they cross over a long bridge supposed to signify Brooklyn, but is in fact, The Golden Gate Bridge in San Francisco.
Factual error: The way that Charlie makes the skeleton move is way too complex to be controlled merely by a basic remote controller (which looks like it was originally for an RC car of some sort), which can only control up, down, left and right.
Factual error: This movie takes place in 1957, clear from the Sputnik reference, but at the dance they play "It's All in the Game" which didn't come out until 1959.