Other mistake: When Costigan drags a handcuffed Sullivan into the elevator, Costigan slams Sullivan against the wall and his left arm is visible and not in handcuffs. (02:13:05)
Other mistake: When Anthony Anderson is shot in the head towards the end of the film, you can see him still breathing as he lays on the ground.
Suggested correction: It's unsettling, but sometimes a lethal head wound leaves the base of the brain that controls autonomic functions like heart beat and breathing intact. These victims may wheeze, bleed profusely, or even convulse vigorously for several minutes before expiring.
Other mistake: When Jimmy Bags reaches for his cigarettes, Billy's gun hits his forehead. But after the cut to French's face, Jimmy Bags is spitting up teeth. (00:43:00)