Factual error: In the scene where there is a train passing, the cars are marked "Burlington Northern." There was NO Burlington Northern until 1970, 7 years AFTER the shooting.
Factual error: Morrison did finish film school in real life. He did not drop out as depicted in the film.
Factual error: Pierrepoint is depicted as having a London accent. In real life, however, he was from the north of England, and had a Yorkshire accent, which sounds completely different. This is proved in a BBC interview with him, dating from the 1970s.
Factual error: As Father Laforgue walks in town at the beginning of the movie (with a better, closer look a minute later before the scene changes), you can see that despite the "Quebec. North America 1634" caption, they have on a pole the contemporary flag of Quebec, designed only in the 20th century. (00:01:55 - 00:02:30)