@Val Killmore,
And...even so...and that he did that in such a fashion ... is proof of what? That he was not insane or that was sane enough to understand consequences? Can't decide that, IMHO.
However, that itself is a moot point, too. He's dead so there's not going to be any trial against him or his family.
So any thoughts that he lived out a video game 'for real' in his mind ..and fantasized it all to be part of an fantasy killer video game is indefensible, unprovable and furthermore irrelevant.
However, there could be some sort of potential future trial should a few scenarios play out:
1. if an autopsty revealed that he clearly was on medication that
could create a psychosis or acute schizophrenia that produced hallucinations.
2. if he was being treated recently by a shrink for schizophrenia or violent outbreaks. maybe you can haul his shrink into court, but not sure that'll be productive in any meaningful way.
You can probably toss out the success of such a lawsuit, though, because any good pharma company with a team of lawyers will say show the court undeniable proof that what he experienced was acute schizoid or psychotic state and the drugs caused it.