Revealing mistake: When Jack and Ennis are cliff diving naked, if you look closely at Jack when they both run and jump off the cliff you'll see that it's not Jake Gyllenhaal but rather his stunt double.
Brokeback Mountain (2005)
1 revealing mistake - chronological order
Directed by: Ang Lee
Starring: Anne Hathaway, Jake Gyllenhaal, Randy Quaid, Michelle Williams, Heath Ledger
Continuity mistake: In the second tent scene, just before Jack and Ennis kiss, Jack's left arm changes from being at his side in the first shot of Ennis (as Jack touches Ennis' face) to up around Ennis' neck in the second shot of Ennis (after we see Jack's face). Also, Ennis' left collar goes from flat to sticking up during the scene. (00:32:30)
Jack Twist: That's more words than you've spoke in the past two weeks.
Ennis Del Mar: Hell, that's the most I've spoke in a year.
Trivia: Although Heath Ledger plays Kate Mara's father in the movie, he was only four years older than Mara.
Answer: Lureen may have been lied to about how Jack died. As a kid, Ennis had seen the body of a man that was killed for being gay. Knowing that Jack was 'seeing' other men, Ennis knew that he must have been killed for that reason instead of the way that Lureen explained it. Even if she did know the truth, she may have lied to him because she didn't want Ennis to know how Jack really died.
Jane Doe