Deleting class document does not delete from xwikiclasses(prop)

I've noticed that if I delete a class document, xwiki does not delete the entry from the xwikiclasses table, nor does it delete the properties asscoiated with that class from the xwikiclassesprop table. Thus when I recreate the class document, all the old properties are still there.

I didn't actually have any object instances at the time I deleted it, but I just tried deleting a class doc that did have an object instance and it still allowed me to delete the class doc with an instance of the object existing - after which the instance was visible in the other doc's object editor, but clicking on it did not display it.