Earlier quoted context omitted.
The mustache-twirling cartoon villain implied by the narrative. People aren't that simple, not even tech managers.
It's not mustache-twirling villainy, it's just having a fragile ego and being pissed at a dig at you, which is common across all sorts of people, managers included.
A simpler explanation is that an aggrieved party is not giving us the whole story. General advice: Be wary taking sides in nasty breakups even if (especially if) you want to like/dislike one or the other.