Here is an extreme example [requires 10k privs to view].
Are these likely to be undelete votes from the very user who asked the question?
Probably. As long as it wasn't deleted by a moderator, any 10k user, as well as the OP, can vote to undelete the post. The OP likely pushed the button thinking the post would be instantly undeleted and was disappointed to see that's not how the system works.