Posting on a social news site is a privilege, not a right. I've had stuff removed from Reddit and a few from Hacker News that got flagged after going on the front page...I've had stories on Reddit that got many upvotes and still removed just as it was going viral because the mods didn't like it...it's just the way it goes. It def. can seem unfair at times. No question about it.
That said, the author wasn't complaining; just doing analysis and pointing out an oddity which was of interest given the context of their research.