I think it's just bad luck for the purchaser. If it worked when he collected it, and he left positive feedback .... well it was all good when he bought it obviously.
I have learnt the hard way about giving eBay refunds. Two sales - a PC mobo and a mobile phone - I had the buyers contact me 1wk after to say they were faulty.
I refunded their money. Imagine my surprise when both de-listed from eBay on receipt of their refunds. The mobo had been cracked by the use of too much force (buyers fault) and the mobile had been attempted to be modified (what for I don't know) and broken.
So now I always state in my auctions "there is no warranty, what you see if what you get, if you are worried collect it and I will demonstrate it working".
