EDIT: To be clear, Ruberik is NOT an impostor, and it's sad that someone is now going around flagging his comments.
No user flagged those comments. Some comments (e.g. by noob accounts from Tor IPs) are moderated by default because of past activity by trolls. These eventually get unflagged. We're going to open the unflagging part to the community soon, but that work isn't done yet.
Looks like his comments are un-flagged now.
Also, as others have pointed out, Peter Norvig mentions some of this in his talk.