How about he was a crazy son of a bitch.
But he sure didn’t act like some crazy violent SOB. This guy seems to be a sleeper, quiet, isolated, wealthy..Airplanes, multiple homes, High roller, then sends the girlfriend 100k before publicly detonating? Got it pretty damn good so why not kill and wound scores of people?
Btw, I could just see the Sheriff stand up there and state what you said as the motive.