The post was placed on the front page via second chance pool (https://news.ycombinator.com/pool, explained here https://news.ycombinator.com/item?id=26998308). This happens all the time on HN.

The voting is legitimate; there's no evidence that the voting is from sockpuppets or anyone else connected with the team/project. We always monitor the discussion and the voting, and if the discussion is not of sufficient quality, the post will not stay on the front page for long.