I checked the box next to "Delete all votes" saved the node and votes were not deleted. Should/can votes be deleted in another way?
I looked at the code and there's only code that makes the checkboxes appear, not code that does the actual deleting.
One could conceivably delete votes through the database, but you should backup your database.
DELETE FROM pollfield_votes WHERE nid = 4254;
Otherwise, code is needed to implement this feature.
Drupal is a registered trademark of Dries Buytaert.