The k-soc terms of service state:

Harassment, hate speech, or any other form of harmful behavior will not be tolerated.

Now, I can't read ernest's mind to determine what he meant by this line exactly, but this kind of mean spirited, bad-faith jab falls under "harmful behaviour" in my book.

Way back in the way back we used to call comments like that “flame baiting”. It’s trying to start a fight, nothing more. Forums and BBs I moderated used to technically ban it, but generally the rule has always just been “don’t feed the trolls”. Meaning: don’t comment, don’t downvote, don’t bother reporting. They just want attention, the only thing that hurts them is realizing that this board will ignore them just as completely as their parents already do in real life.