It wasn't one post, it was several posts over the course of several days if not weeks.
We all have bad days, but you still need to hold yourself together as an adult. I've seen blue collar guys get away with stuff like that, but for someone who is supposed to be a professional, those would be inexcusable. The narcissistic melt downs are.....let's say "highly unprofessional". I've worked at more than one employer where a single one of his outbursts would have resulted in immediate termination.
"not everyone who’s struggling is ungrateful or negative."......ya, I'm going to lean towards the latter in this case though.