I think the buyer is just finding a way to get back at you-sounds like a lot of anger there. Not sure you can win except you probably could get the feedback removed, as others mentioned.

Off the track a little but as a buyer, if i read your shipping conditions it would put my back up to tell the truth.

This stuff about how you will accept no responsibility if items aren't insured-I am not sure how well that would stand up.

If I didn't get my item, or if my item was damaged in the post, I'd still be putting in a claim.