I think what happened is that he tried to post to a subscribers-only board. His posting pattern (10 yesterday and 3 today) doesn't indicate he'd have run afoul of the no-reset-while-posting-at-midnight bug.
Unless the bug that was counting edits as posts isn't completely squashed and the system told him yesterday that he'd reached his daily limit. That message is quite different from "Got a message today that said if I want to post here I would have to pay...", though. When that happens, this is the screen that you get: