Mafia producer is making a big mistake. He was dealing with an avenger, who doesn't care about anything but his specific revenge. In the world of shady business, that would actually be the safest wacko to deal with, as long as you don't happen to be the target of revenge, of course. If you are dealing with blackmailers or anyone else who cares about money, then you'd never know when they would backstab you as well. But an avenger has zero reason to do it, as long as they are happy with their vengeance. But if you add yourself onto their list, then you make the worst kind of individual enemy.