Listen. Its sad; a young kid died. That is sad, I got a young son at home. Its horrible. But guess what? Thats not how the legal system in this country works. We are a nation of laws. Ivy is right, at best imperfect self defense ie voluntary manslaughter. AT BEST. The prosectuor overshot, all the lawyers I know that are knowledgeable about criminal law say that if the defense had chosen to say "were not defending this" they still would have won because the case doesn't meet its burden.
The man deserves an acquittal, and if my bookie took action on this sort of thing Id lay cash down on an acquittal.