I'm not sure what you're referring to, but if it's the ranking of the current submission, that's because users flagged it, which is the usual reason why stories drop in rank.
As for comments by people with domain knowledge, I was just looking at this a couple weeks ago. Here are a few I randomly ran across:
https://news.ycombinator.com/item?id=22025961 ("I'm the lead author on this paper")
https://news.ycombinator.com/item?id=21997642 ("I can remember when I first met Gary [Starkweather] in 1988")
https://news.ycombinator.com/item?id=21906624 ("I’m actually one of the architects of this processor.")
https://news.ycombinator.com/item?id=22012453 ("I'm a dentist who regularly treats OSA with dental appliances")
https://news.ycombinator.com/item?id=21963509 ("As a working scientist" followed by "Biology postdoc here")
https://news.ycombinator.com/item?id=22127746 ("I'm an anesthesiologist")
https://news.ycombinator.com/item?id=21744337 ("I wrote the original software for Long Bets")
https://news.ycombinator.com/item?id=21670257 ("This is my father's family doctor and was my doctor throughout my childhood. He actually birthed me")
https://news.ycombinator.com/item?id=21635488 ("I was the person who blabbed about the top-secret _callback parameter the weekend Pipes launched")
Edit: from a few minutes ago – https://news.ycombinator.com/item?id=22148337 ("I am a computational cognitive neuroscientist")
Edit: from a few hours ago – https://news.ycombinator.com/item?id=22146986 ("I'm a researcher working on exactly this problem")
Edit: https://news.ycombinator.com/item?id=22141584 ("I’m a b-school prof/associate dean")
Edit: https://news.ycombinator.com/item?id=22148438 ("I used to do the soil lab testing for a guy that dealt with this waste in my state.")
Edit: https://news.ycombinator.com/item?id=22161404 ("I started this project")
Edit: https://news.ycombinator.com/item?id=22172066 ("I was a grad student at the Media Lab in its early days.")
There are tons of these, many of which don't get much notice. We've periodically published a highlights list, but I'd like to come up with a way for users to nominate such posts as highlights when they run across them... something like a positive 'flag'.