post #2286392's down_score value is currently 6, when all other posts in the database have a down_score value of <= 0. It most likely happened shortly after the update in 2016 that added the up_score and down_score columns, since everything after post #2284549 has score === up_score + down_score.
If there's any other database quirks/inconsistencies anyone like to check on, from what's publicly available, I'm open to requests.