This guy is clearly snooping the downvoters as an instance admin and retaliating against them. Wouldn’t even have noticed if I didn’t stumble onto the modlog in Voyager by accident.
I might be of course wrong in my assumption. But I don’t remember ever interacting with anyone from that instance, I’m not subscribed to those communities and the dates correlate.
Probably, but maybe they like it that way so they can deal with the users who do it.
Downvotes still federate even with downvotes disabled, so disabling them on your instance is more a visual thing for your own users, since they still get relayed to other instances even from local posts and local comments.