This Kimberlin guy should be in jail if they can pin this on him. I'm sure there are many statutes in many states that prohibit the use of emergency personnel in this way.
So, my guess is that they cannot pin this on him. I thought even the throw away phones can be traced to an e-mail account (to activate) that can be traced to the purchaser. I'm sure the FBI or other federal agencies could get to the initiator of the hoax.