I was looking in the delete tab, and saw this question showing 1 undelete vote (30 day view), but the question shows 2 undelete votes in the question itself. It doesn't appear that the post was undeleted by anyone previously.
If there is an undelete vote older than 30 days, then there really ought to be a "max" or "all" view in the delete tab so we can see how many votes there actually are on those questions.
Do delete/undelete votes decay like close votes and flags do? (I couldn't find this in the FAQ, so that should be updated regardless.)
Is this somehow related to this problem?
I'm not sure if this is a bug report, or a support question, or a feature request... I'll edit when I get more information from the answers here.