wp-cron still running on deleted sites

We have a multisite installation with about 650 sites. We’ve noticed that wp-cron is still called on some of the “deleted” sites, which produces a 410 error in our apache logs. Example:

<some ip> - - [09/Oct/2013:11:59:56 -0400] "POST /<some site>/wp-cron.php?doing_wp_cron=1381334396.6046869754791259765625 HTTP/1.0" 410 4171

We’ve disabled all plugins on this site but the problem persists. We tried installing WP-Crontrol to inspect the cron jobs on the site but couldn’t reproduce the error from there. It doesn’t cause a load issue but we’re looking to install OSSEC on the server and we’re concerned that multiple 410 errors in succession would cause OSSEC to block the server from itself.

Any guidance would be appreciated.