Factual error: When the Ranger trainees first meet Samuel L. Jackson, he's wearing the rank of a Specialist on his collars even though he's a Master Sergeant. Title 18, Chapter 33 of the US code prevents the unauthorized wear of a military uniform (among other things), however this does not automatically correct the mistake since a common misconception is that one slight alteration is sufficient to make the uniform legal. Having the wrong rank on is too obvious of an alteration, especially for anybody who has spent more than a day in or around the Army and would still be punishable by law, if he was dressed in an attempt to fool your average citizen outside of a movie.
Factual error: Sarah Polley is dying of cancer. She's not told anyone, and the film is about completing her list of things to do before she dies. There's a scene where she's talking about children with her neighbour, a nurse, the woman who she eventually 'sets up' to replace her, to look after her husband and children, when she's died. The nurse refers to a truamatic incident having nursed Siamese twins in hospital, who both die. She describes how one died before the other -the boy, then the girl. This is medically impossible, as Siamese twins are always the same gender.
Factual error: Mahony gets Can$15,000 from the bank he works in in Canada and flies to Atlantic City (US) where the cashier gives him US$15,000 of chips. US and Canadian dollars are not equivalent and, at the end of 1981, the cashier should be giving him less than US$13,000. Since he is broke, he couldn't have made up the difference himself. (00:09:30 - 00:11:30)jle
Factual error: Many of the "western" products used in the film are in packaging from the present day, not from the time the film was set (1989-90). For example, Coca-Cola Light had a white label then, not the silver one in the film. Other examples are Jacobs Krönung coffee and Heinz ketchup, shown in recently redesigned packaging.
Factual error: At the end of the film, Aubrey sends the de-masted prize Acheron to Valparaiso, Chile, for repairs. Valparaiso is 3,000 miles from the Galapagos Islands, and, in 1805, was a tiny village without appropriate port facilities to dock or repair anything as large as a frigate. Valparaiso did not become a major port until after Chilean Independence from Spain (1810). Guayaquil (in modern Ecuador) would have been a more appropriate choice, being about 750 miles from the Galapagos, and being a major port in 1805. The choice between the two ports was moot, anyway, since both municipalities were Spanish territory in 1805, and thus were allied with the French, and hostile to the British.
Factual error: Lots of liberties are taken with the geography of downtown Portland. For example, at one point Bonham is standing on a fountain looking around and, from his point of view, you see two MAX trains on a slope going past a parking lot. Those two points are about a mile apart and there is definitely not line of sight between them because most of downtown Portland is in the way. (01:07:40)jle
Factual error: After the cops respond to the domestic disturbance (son hitting mom), we see the male officer get in the back with the boy to show him the crime scene photos and he shuts the door after getting in. Police cars are designed so that the back doors must be opened from outside, however, he exited the car with no help.