I guess. Maybe I'm just cranky after looking at the flat-earth thread.I guess its a good vetting question as to whether or not he will continue to ask you questions about the history of the guitar that you may or may not know. Is it so hard to respond "No, I've had it for 5 years", or "yes I'm the original owner. Whatever his reasons are for wanting to know if your the original owner or not I don't see that as an unreasonable request of info.
...and I did respond politely (as I always do).