There also might be a wee bug somewhere distorting the statistics. For example:
http://superuser.com/questions/853276/https://superuser.com/questions/853276/ was closed a month ago, and deleted just under a fortnight afterwards. http://superuser.com/review/close/333318https://superuser.com/review/close/333318 showed it to me just now, claiming that it was still open with 2 close votes.
For another example:
http://superuser.com/questions/863208/https://superuser.com/questions/863208/ has no close votes at all. http://superuser.com/review/close/329125https://superuser.com/review/close/329125 just showed it to me claiming that it had been marked as "unclear what you're asking".