To answer your exact question, if they did have the email, they would have a very good chance at jacking it.
When I hear my friends and stories about jacking PSN's and all, the PSN people always ask for your email to the account you're trying to get back / jack.
But with everything I have seen, heard, and had gone through myself, there's a very VERY good chance its possible.
They could do this with the original email of the account was created on, and the current one I am pretty sure.