A lot of ebay sellers are not professional sellers;i.e-they do not have the skills necessary to sale things successfully anywhere but ebay - they can't separate emotions from necessary seller protocol. As a result, you have guys like this who probably had a few autographs questioned and then finally blew a gasket.
Of course his reaction is crazy, but I sort of get it. I've had four or five return requests in the last couple of months (highly unusual and just a coincidence) and the reasons were all obviously based on an assumption that I would not give a refund, so some bullshit was included in the original messages. Given that I give refunds for ANY reason, no questions asked, and very clear scans of all sides of any item are provided, it's irritating to have someone claim that an item is damaged, not as described, fake, etc. - on a bad day such behavior will piss me off quite a bit. Just ask for a refund and you get it. It's tempting on 'bad' days to say "fvck you - keep the item", but while I don't do that, I think some people do. Any number of other reasons for his behavior - he might have a terminal illness, just had his wife walk out the door, gone back and forth on the internet with a troll for the last week
, very sick child, etc. Cut the guy some slack and move on the next auction.