Many of Mark Wahlberg's lines were improvised. Garrett Hedlund had difficulty improvising his lines, so director John Singleton and Mark Wahlberg helped him through it.
During the Thanksgiving dinner, only Bobby does not "see" Evelyn. This is due to Bobby refusing to accept her death.
The bathroom scene took two days to shoot. For twelve hours a day, Mark Wahlberg rested his bare bottom on a cold toilet, Garrett Hedlund stood in a hot shower, and Tyrese Gibson wore nothing but a robe. Mark Wahlberg had to be helped off the toilet at the end of each day, and Garrett Hedlund's skin peeled and pruned.