Character mistake: After Pookie is killed (with his eyes open) and the bomb is strapped to him, he blinks his eyes.
Character mistake: When Garrison is leaving the house to question Clay Shaw on Easter Sunday, his wife is complaining about his working on the Sunday, and at one point calls Garrison 'Clay'.
Character mistake: In the scene before the New Haven concert, when Jim is talking with the reporter/ love interest about his school history, she comments that Jim attended the University of Florida. In actuality, Jim attended Florida State University.
Character mistake: When Dolph is looking at the logo for the Red Dragon brewery, he says, "That arrogant scumbag mother fucker. He put the yakuza iron claw right on the logo." But, the iron claw is not the logo of the yakuza. It's the logo of the specific syndicate run by some members of the yakuza, as Dolph stated after ripping open the shirt of that guy in the interrogation room. So, he just wrongly stated what the logo really belonged to.
Character mistake: Gail is interviewing Nick on the steps with a tape recorder. You can tell she's holding down the wrong buttons. The record button is in the up position. She's not recording anything.
Character mistake: We see in a flashback (so, early 1600s) the protagonist with his mother in Ruen, back in motherland France. She tells him she is praying to St. Joan (d'Arc; they are in front of a statue of hers). Joan d'Arc wasn't canonized until the 20th century. You could argue that in the eyes of the laymen she was already considered a saint. However, her son does not object and considers her a saint as well, doubling down on the statement even later on in Quebec when he does not have to humour his mother, and he is a Jesuit. He obviously should know better. (00:35:25)
Character mistake: At the beginning of the movie, during "Provincial Life", we see a fat lady trying on a hat in a hat store. The sign over the window, in French, reads "Chapeau" (hat). The correct way to identify that store would have been "Chapeaux" (hats) or "Chapelier" (hatter).