My reputation went up by 13 points today, due to an answer (to an old question) being simultaneously accepted and downvoted. Of course this could be a coincidence, performed by two different users.
But assuming for a moment that it is not (I mean, what are the odds?), can anybody come up with a reasonable explanation for this? Is this perhaps a result of showing people's accept rate (e.g. the OP doesn't like my answer, but does want a high accept rate)? Have you ever done this?
(This question is slightly related to "Accepting answer without upvoting?", but none of the answers in that thread discuss downvotes.)