Typical for HN, the article got hidden. It's well known YC alumni have some additional HN mod permissions and Docker is YC S10 (Summer 2010 batch of YCombinator).
Moderators didn't touch this article or affect it in any way; users flagged it.
YC alumni do not have HN mod permissions or any ability to demote articles beyond the flagging ability all users get (once their karma passes 30).