Terry: It is what it is.
Vincent: "It is what it is"? Everyone's saying that now. You know what it means? You're screwed, and you shall remain screwed.
Vincent: Don't ever become a pencil-pusher kid, they're spineless.
Zucko: Come on, Vinny! Why do you always have to do things the hard way?
Vincent: It's more interesting.
Zucko: And a lot more painful.
Ocinski: Hey, uh, your dad the one that taught you how to fight?
Oliver: No, my babysitter.
Answer: They left ASSUMING he was dead, AND had been the CAUSE of it. The dumbest thing they could have done was return to the scene of the crime if he actually WAS dead Since you can't collect from a dead guy, the filmmakers wish you to assume they just chalked it up as a loss. He wasn't their only customer I am sure.