In the commentary, the director and producer mention that many of the best lines in the film were improvised by Denzel Washington and Mark Wahlberg.
Paula Patton's second nude scene. It was her idea to go topless when she's in the bedroom with Denzel Washington, because she said it didn't make any sense why she'd have a bra on after they just had sex. She joked in an interview that it didn't make sense to have her panties on either, but she said there was only so far she'd commit to the scene. She appeared nude earlier in another movie where she acted along with Denzel Washington, called Déjà Vu.
The screenplay for this film was featured in the 2009 Blacklist; a list of the "most liked" unmade scripts of the year.