Not sure what I would have done.
Maybe let him off the hook if he forked over the full asking price. And told him never to contact me ever again about anything.
If not, I hope I woulda snapped a photo of his mug and listed his info in the same craigs section as the bike was listed. Chances are good I'd have his ID during his test ride.
No one has ever ****** with me during or after a sale. I make it pretty clear in my ads I know my bikes inside and out.