7:12 AM
@C.E. Huh thanks for bringing that up, I didn't get notified by his comments (I suppose because he @'d me without my involvement in the question)
He did unaccept my answer on his previous BorderingCountries question
and IIRC if you unaccept an answer, you can't re-accept it without an edit to the answer or something like that.
but he should be able to accept other answers.
Unfortunately for some reason I find this user a little draining to deal with (not the user's fault) so I'm unwilling to get involved any further.
Uncharitable of me, I know :(