Although I agree it has probably not been professionally repaired, if at all, I think the feedback maybe somewhat harsh unless the winning bidder has actually viewed the bike in the flesh. I'm not defending the seller or his attitude but you can't tell a great deal from the photo's and the seller never forced anyone to bid unless they were happy to do so.
So you deliberately bid on something you had no intention of paying for and then trashed the guys feedback on a transaction that never actually took place.
all very valid in my view, but has avoided someone being stitched up and a lot of hassle afterwards, I had a lot of hassle with a non cycling item where the seller was guilty of a number of mis-descriptions and you wouldn't believe the time taken to resolve these things after the event (albeit not helped by cash on collection). If he can prove comment is invalid he can probably get ebay to remove ?