We answer questions about this kind of thing all the time (literally many times a day), both on the site and via email (hn@ycombinator.com). There's no question like this you can't find out the answer to. Whether you want the answer, or like the answer, or choose to believe the answer, are other questions.
The fact that there can be a thumb on the scale is (or should be) well known by now. Since the thumb is invisible, though, we can never truly know unless it's directly addressed, which was the case with this one. +1 to the other commenter's suggestion of visibly marking manual moderation activity (vs. algorithmic voodoo which is more understandably opaque). We've already got the [flagged] tag that transparently shows end-user moderation activity.
