Continuity mistake: When Hoffa is eating an ice cream and JFK is shot he stands up and the spoon swaps between being in a 9 o'clock position to a 12.
Factual error: When they pull up to the house in the red Marquis to kill Hoffa, the front license plate has Michigan plates from 1973. Hoffa disappeared in 1975.
Other mistake: Russ pours olive oil on a salad, says it is the best vinegar, and after the next cut he grabs the olive oil again.
Chosen answer: First off his name was Chuckie O'Brian. Jimmy Hoffa wasn't his biological father, he was more in the nature of a foster father. Second, he probably knew what happened. What was Chuckie going to do? It was a sanctioned hit. And if he went to the police he would have ended up the same as Jimmy Hoffa. They put him in the middle of it to keep him quiet. If he goes after the people who did it, he's as good as dead. If he talks he could end up in jail with them, and the mafia will probably kill him anyway.