The couch in the loft living area has a painting on the backrest of Derek, Jones and Travis; the mouths on the characters are blurred out deliberately.
When Beau and Derrick are fighting outside of Naomi's apartment building, they collide with a door beside some greenhouses and plant supplies, and the door cracks against their weight. During the commentary, the actors and director themselves reveal this was a mistake.
During the fight between Beau and Derrick, Beau punches Derrick in the face, but James Marsden's head moves in reaction to the punch before it has even landed.