You do realize he copied your comment, don't you?
https://news.ycombinator.com/item?id=11837687
(I think there are others, but I can't find them now.)
Maybe it was some bot, but that's an odd bot.
It could be a bot tactic to build accounts with karma that can later be used for astroturfing, using proven comments from elsewhere. Maybe governments and organized astroturfers have automated that sort of thing more than we think.