The Room (2003)

Factual error: When Johnny commits suicide in the end, the slide of the pistol doesn't move when it fires. (01:33:00)

Trivia: Greg Sestero is called Mark as a misguided reference to the actor Matt Damon and his film "The Talented Mr. Ripley." Writer/Director Tommy Wiseau was very taken with the film, and decided to name a character after Damon... however, he misheard "Matt Damon" as "Mark Damon" once during a conversation, and thus wrote the name "Mark" into his script for "The Room" instead of the proper "Matt." He never bothered to change the name to "Matt", thus making his intended reference null-and-void.