I wonder if the bike was his or was it rented? Ide assume it was rented, so who ever he rented the bike from would have his details etc, if say he borrowed the bike from a friend they would also know, or was it his own bike? Was it registered in his name etc? I've been doing exactly the same as this poor chap, but I always keep my bike licence, insurance etc on me at all times just in case of an accident or being stopped by the police etc, its sad what has happened & more so when the family is left in limbo......
Just a thought, he may have just popped out to get some cigarettes etc & forgot to take any i.d etc.......