If the question is asking if Mr. Massee died simply to avoid facing criminal proceedings 30 years for an accidental death, that just doesn't seem likely. If, however, the question is whether or not his death will get him out of any future proceedings, the answer to that is undoubtedly yes.
It was an accidental shooting. The death of Brandon Lee could have been prevented, but it was likely poor safety measures, rather than Michael Massee who had anything to do with Lee's death. Massee may have pulled the trigger, but he did not know the gun was loaded with real bullets.
To put it simply: Accidents happen every day. I see no reason why Michael Massee would have wanted Brandon Lee to die. It was a gun that he was paid to point at a fellow actor and pull the trigger. He did so and it just so happened to be a loaded gun. It could easily have been any of the other actors who picked up that prop gun that day. I'm not saying Brandon's life doesn't matter. I was actually a huge fan of that movie and was saddened while learning of his death over a decade ago.
I don't think it's right to say that Michael Massee avoided criminal proceedings. If anyone should have been charged with any crime, it would be the person who improperly loaded the gun. But I don't think anyone is at fault in this situation. It was a very unfortunate accident that no one was directly responsible for.