Not really... if you don't like their offer, make a counter offer or hire a lawyer.... By the way, with all due respect, your statement that "The police report stated that the accident was 100% the fault of the driver" cannot be true because police do not determine fault due to an accident...
wHAT HE DID IS ILLEGAL. hE SHOULD HAVE GOT A TITLE FOR THE BIKE WHEN HE BOUGHT IT. hE SHOULD THEN GIVE YOU THE TITLE IF YOU BUY IT. WITHOUT A TITLE ALL YOU ARE DOING IS BUYING YOURSELF TROUBLE. eITHER INSIST on a valid title or run, don't walk away from this deal.
Sorry for the caps