Kevin Connolly was supposed to play Justin, but due to his first child arriving soon he recommended Kevin Dillon who got the role.
(at around 1h 23 mins) Gary gives Officer Bruce the deactivation codes for the two explosive vests. One of them is 040478. That's Romuald Boulanger's (director of the film) birthdate (4 April 1978).
(at around 57 mins) Not only did Gary mention himself being played by Joaquin Phoenix, but immediately afterward Mel Gibson grabs a baseball bat just like Joaquin's character does in Signes (2002).
(at around 57 mins) Gary mentions being played by Joaquin Phoenix in the movie version of their game. Mel Gibson and Joaquin Phoenix played brothers in Signes (2002).