Last modified: 2014-11-01 22:03:10 UTC
https://www.wikidata.org/w/index.php?title=Q43303&action=edit&restore=9070950 gives: PHP fatal error in /usr/local/apache/common-local/php-1.21wmf10/extensions/Wikibase/repo/includes/actions/EditEntityAction.php line 220: Call to a member function getEntity() on a non-object
This is because the revision trying to be restored to has been revdel'd. See https://www.wikidata.org/w/index.php?diff=9070950 This should probably fail a bit more gracefully though.
No longer an issue apparently.