You know, I don't think he could have, either. But my question isn't really about canonical (if that's a word) believability or anything. We don't have to use Voldemort. Say...Laurence Simmons had all three of these things happen to him. Which, ultimately, would be more painful? The Cruciatus Curse is supposed to cast unimaginable pain on the victim, but ripping one's soul and losing one's body are also, as Aida said, against natural order and must cause loads of pain.
EDIT: This is supposed to be the fifth post, after Aida's second one.