well at least I did say my info is based on tabloids ....
As far as a dutiful neighborhood watch, my understanding is he made a call to authorities (a good NW thing to do) was told to not pursue, decided his judgement to be better than professional instructions and pursued (disregarding expert legal authority, less than stellar NW behavior). To insert himself at this point is, from my tabloid perch, is meddling and up to no good. Since I said almost maniacal, I suppose that means he wasn't maniacal, the distance from that which constitutes "almost" a matter of ones own value interpretations.
NW folk who do it in the good spirit of NW serve as eyes and ears, not as intervening well armed first-responders. It does not seem to be in dispute he was asked by authorities to stand down, he did not. He inserted himself in a manner that NW should not do. Why not insert? See outcome.
Certainly, it seems to me this guy is aquitted, there is no witness as to what precipitated him getting beat up by M, certainly he sought M (not in dispute) and certainly he got beat up for pursuing M (something at least I do not dispute, but, I really haven't poured over the details and timeline of whether he could have self-inflicted this damage post homicide). Enough other info (not in dispute) seems to indicate the most likely thing is M was beating up on this guy who was following him (and maybe physically starting a fight, but there is no evidence).
Disregarding authority and choosing to pursue somebody while well armed speaks towards a state of mind that I will not dismiss. He was told not to do it (not in dispute), he did it (not in dispute). Those that told him not to were experts. Deliberately ignoring expert advice and committing to a specific course of action against expert advice that precipitates death constitutes manslaughter in my lay opinion. My lay understanding is that manslaughter is when a course of action results in death when a 'reasonable' person would recognize that the course of action had a unusal risk of death or significant bodily harm. An authority, with expertise, told him not to. He did. That is what this should be about. i.e. some lower version of manslaughter likely to include a sentence of nothing but probation (or maybe a couple months in county) and a loss of the right to carry a weapon during probation.
| 
