What fascinates me about it is the psychology of it all.

That guy had nothing to gain, nor anything to lose, in your interaction with the other party. So why was he willing to invest so much clearly emotional energy into it? It's almost like he wanted to have the aggressive interaction simply for aggression's sake. Like he needed to feed on the aggressive emotions or something? There just doesn't really seem to be any sense in this whole thing?

There's a certain type of person who sees niceness or agreeability as weaknesses, and not strategies for cohesion.

Nah, it's signaling. Being nice, to the angry person, undermined the social cohesion of the people asking for change from the company and marked the person being nice as a potential weak link that the company could placate to divide and conquer the opposition.

That's pretty much it. They wanted a mob.

Not getting a mob means everyone goes home, bored, probably alone, and doesn't get to participate in making changes.