We didn't see it or demote it—it set off the flamewar detector. I've turned that off now, in keeping with the principle described here: https://news.ycombinator.com/item?id=41511529.
p.s. @dang is a no-op - I only saw this thread because I was doing our standard review of the flamewar detector. If you want guaranteed* message delivery, hn@ycombinator.com is the only way.
* Well, mostly guaranteed. I assume there are a few that fail to get noticed in the spam bin, though we check that pretty carefully.
It has one public-facing moderator (and apparently a few others who don't post publicly on the site). HN's own mods see very little of the total site content. Automation and member votes, flags, and vouches, as well as emails to the mods, are what keep HN humming. Not perfectly, but quite frankly one of the better-run online discussion sites, and one whose quality has remained remarkably steady over nearly 20 years.
If you see something you think isn't right (bad content not flagged, good content flagged, whatever, email the mods, and they'll take a look. I do this a lot myself, usually with positive results.
Note: we still moderate such threads. We just do it less than we otherwise would.