Continuity mistake: Near the end, when the hitman walks out of the diner, the camera focuses on the car in the parking lot, cuts back to the hitman, then cuts back to the car. The problem is the shadows in the first shot of the car are about half a meter long, but a few seconds later they are two meters long. Obviously both takes of the car were taken hours apart.
Factual error: When Jimmy Hoffa is convicted in 1964, he is driven to the penitentiary in a 1967-68 Chevrolet Suburban.
Bobby Ciaro: Someday, your gonna be president of the United States.
Jimmy Hoffa: Fuck that. Someday, I'm gonna be president of the Teamsters.