Jack doesn't die. He uses his brain just like he taught matty. He works with the FBI, or a rival gang, or other boxers who've been screwed over, and mobguy goes down instead. Jack's in the clear with the mob, but he's traveling to fights all the time. Maybe he puts Matt in a special school. Maybe he's just inattentive. Stick still gets his mitts on Matt. Jack finds out what kind of "teaching" his boy is getting. The insults, the cruelty, the broken bones. And Jack lets the devil out.