Sometimes I just don't understand the deal with not registering your bike. In CA all it takes is to fill out the form Reg230, a check to the DMV for $19.00 and a first class stamp.
For want of taking the above action he has lost his bike. The tow and storage fees will quickly approach $400.00, and when the tow yard sells your bike you are still on the hook for the difference between what they sell it for and what you owe.
It is just not worth it to not register it.