If you'd prefer an admonishment which specifically points to that, try: <https://news.ycombinator.com/item?id=13213514> or <https://news.ycombinator.com/item?id=14435528>.
You can search/review others yourself with: <https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...> (dang) or https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...> (sctb) or <https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...> (tomhow), with well over 100 examples in that set.
and quite frankly i disagree that asking for explanations when you downvote is the same as complaining about downvotes because that again could have been worded as: "if you disagree please explain". would that make a difference?
the point is just using the word downvote should not be the trigger but how the message is worded overall. there is also a rule about charitable reading. i read that comment and if i ask myself, is that person complaining about downvotes, my reading is, no they are not.
frankly i find people complaining about other people talking about downvotes just as bad. so i think this whole subthread is in violation.
but to end with something constructive, i think a better response to the initial comment would be:
mentioning downvotes triggers people and drags down the quality of discussion (as this thread here now pretty much proves). if you want to express that your opinion is controversial, maybe just state that, or, even better, just leave it out and focus on your actual message, regardless of what you believe others will think of you because that too can distract from the actual discussion that we want to have here (again, this thread is proof of that).