That's an odd analogy. John was a drunken asshole a couple of times in LA, but being a drunken asshole in a foreign culture where nobody knows you is quite a bit different. I'm not saying the murder of this guy was justified, only that the analogy doesn't fit.
John showed that personality trait throughout his life (Germany, London, and LA). Hardly a weekend bender while he was out on the town with bad boys during his split from Yoko and his band.
Instant Karma might’ve caught up with John if a deranged fan hadn’t.
The “wise” “man of peace” BS ascribed to John Lennon is mythology.