Factual error: The opening shot (of the New York Stock Exchange's trading floor) has the subtitle "1985," which might lead one to expect that at least the action in the first few scenes takes place in the year 1985. However, when Charlie Sheen is talking to his Nimrod broker buddy the Nimrod jokes that the day the Challenger exploded, Gekko was on the phone "selling NASA stock short." The Challenger exploded in January, 1986, not 1985. [An explanation for this: Wall Street, as conceived and filmed, was supposed to be set in 1987. However, near the end of 1986, The Ivan Boesky insider-trading scandal hit, many rules were changed, and acknowledging those events would have undone much of the plotting of the movie. So the movie was shifted back in time to 1985 (before the scandals, and also before the Challenger disaster), thus creating this major goof].
Factual error: In the warehouse scene with the wooden crates with maple leaves, even though a correction has been submitted saying a maple leaf was valid, the real mistake is the type of maple leaf used. The film shows a modern graphic style of leaf that did not come into use until the 1960s and appeared on the new Canadian flag in 1965. In the time of Capone, the maple leaves used to depict things Canadian looked like actual maple leaves and not like a stylized graphic.
Factual error: After Robocop stops the criminal from robbing the convenience store by bending his machine gun, the robber tries to run past him, only to get clotheslined by Robocop. The direction the robber flies after getting hit defies all physics. (00:35:15)
Factual error: Ronnie Cox is shot in the heart at point blank range by Brigitte Neilsen, and it looks to me like she's using a large caliber handgun. Keeping track of the action of the film tells us that Cox is sitting up in bed chatting to his friends just three days later. What nonsense. Even if he did survive (unlikely) he'd still be in Post-Op Intensive Care at that stage. He wouldn't be conscious, let alone allowed visitors.
Factual error: After his assassination, Giuliano's body is dropped on the street, and another round is fired into him. In the next shot we see a TV reporter saying something, and there are meter-long rivers of blood running across the street. As he was already dead when he was dropped he wouldn't have bled like that. (02:11:45)
Factual error: When Riggs and Murtaugh are at the indoor shooting range, Riggs shoots a smiley face at long range. Every shot makes Mel Gibson blink and twitch from the bang. No expert marksman would react like that to the gunshot. Nor could his shot placement be so accurate with that reaction.
Factual error: The Police Academy is in an unnamed American city. However, during the opening credits, Mahoney and Jones can be seen driving past a Hudson's Bay store, and the Sam The Record Man, in Toronto Canada.
Factual error: When Clay, Julian, and Blair are driving from Palm Springs to Los Angeles almost at the last scene, Julian dies as they are driving through Joshua tree. That would be the opposite direction to travel from Palm Springs to Los Angeles.