Also, do moderators ever move comments around? I thought one comment was a child to my comment last I looked, but now it's a top level comment to this post. I'm not sure if I am mistaken or a moderator moved things around.
This does happen from time to time. A moderator will "detach" a subthread[1] and move it to the top-level (usually also burying it at the bottom of the page, which tends to silence the discussion).
In this case the comment that was promoted to the top-level has been consistently higher on the page (it’s the first comment still) than the comment it originally responded to.
