Yes, there are lots of user flags, and also a moderation downweight—not for being controversial but for being a quasi-duplicate.
Since front page space is the scarcest resource on HN, we try not to have more than one major thread about a story unless there's significant new information. In this case there had already been three: one on the original report [1] and two debunking it [2,3]. To prevent many incarnations of the same story from dominating the front page (a common complaint about HN in the past), we sometimes penalize these, though never as much as actual dupes.
1. https://news.ycombinator.com/item?id=9714072