People can downvote you for any reason, don't worry about it. If I had to guess, someone may have mistaken your summary as a shallow dismissal of the work. On another note, your reply comment is addressed by two different HN guidelines which is impressive.

Please don't comment about the voting on comments. It never does any good, and it makes boring reading

Please don't post comments saying that HN is turning into Reddit. It's a semi-noob illusion, as old as the hills.

I've been on HN for over 10 years, I think semi-noob is probably inaccurate.

I was just quoting the guidelines. Maybe that's why they hedged it with "semi".