Booking out by phone prior to flight is often a requirement at larger ATC-equipped airfields. At smaller GA fields the booking out provision - that several people here have identified in what used to be Rule 17(2) of the Rules of the Air - is normally done over the radio. I'm not overly familiar with AFISO procedures but certainly at Air-to-Ground airfields there's no requirement for the Radio Operator to log any of the information passed by pilots. So in the context of this accident I don't think there's any relevance to what the pilot may or may not have told Turweston before departing.