Obviously the bullet ****ed him up, that's clear. Still, isn't that like saying that if someone gets whiplash in a car accident then years later dies because of some sort of neck injury, that the other driver is a murderer? Just doesn't sound right to me. I consider homicide to be an immediate thing. Homicide's (according to my clearly non legal definition) that take 30 years to kill someone just doesn't cut it in my opinion.
I'm not sure this has as much to do with the anti-gun agenda as it seems. I mean yes, convenient for that purpose but I remember my dad talking to me about cases he had been aware of where someone dies years and years later stemming from a previous assault by any method. Usually used to circumvent double jeopardy, and honestly...none that evoked much sympathy from me for the attacker. But there has to be a direct link, like someone dying of an aneurism years after a beating. Not someone getting their leg broken then years later dying from a heart attack.
those cases can stem as far as mistreatment in the hospital leading to their death and the perpetrator still being at blame for putting them there. I'm sure my dad demonstrated these cases so as a kid I would think about how far reaching my actions are.