I just remembered a situation with a fellow umpire in a game we were working. It was men's wreck league ball several years ago. I don't even remember the details of the argument and I don't believe I was asked to consult on the call (I was doing the bases).
In any case, the comment in the OP about "ears perked up" (rabbit or otherwise

) applies here. As the combatant was walking back to his dugout, he made some comment over his shoulder and at the end of it added "you pie face". No f-bombs or other obscenities were uttered. But my partner heard this and then literally chased the guy down where more arguing occurred and an ejection finally resulted.
I was watching all this from the middle infield being quite amused and tried hard to not laugh out loud. A couple of half innings later I approached my partner and asked what it was that set him off. He immediately started to get all red-faced again and said it was the "pie face" comment.
I used to watch the Boston Bruins in the late 60s and early 70s and they had a player John "Pie" McKenzie. That's the only reference I've ever heard to being a "pie face".
To this day, I'm not sure what the big deal was with that comment, but it certainly hit a major button for that umpire.
After that game, we took to calling him "Rambo".