Moderators can downweight posts to drop their rankings. Here are 3 examples:
https://news.social-protocols.org/stats?id=41791369
https://news.social-protocols.org/stats?id=41815614
https://news.social-protocols.org/stats?id=41821336
Note the orange line indicating rank, which in every case shows a very sudden and precipitous drop in the rank of each post.
Those threads appear to be stoking the drama more than anything. HN's stated goal is to satisfy intellectual curiosity, and even if the post topic itself is of interest, if the discussion isn't substantive then the system is probably working as intended (regardless of whether it's the flamewar detector or a manual downweight).
I guess these only go back so far? I was hoping to see the graph on my post, which dropped like a stone after a few hours. (https://news.ycombinator.com/item?id=40992654)
There's flagging a post, but that would show up next to the post - do you have any examples?