So....

It all worked out. Not if the card change did it but Reverb decided to pick up the tab. Buyer gets full refund and keeps the pedal and I keep the cash!

I do feel a degree of guilt but that's what Reverb gets for being so hard nosed. I was prepared to refund and accept the item back but just wanted to know what happens if it arrives with obvious damage the buyer committed...They could never answer that for me.

I'm confident the buyer damaged it as I shipped in original box with original packing and the nature of the damage would require a sharp impact which with perfect condition shipping box was impossible....Plus buyer claimed shipped "not as advertised" preventing me from a claim....instead of "damaged in shipping" which would have protected me and the buyer just the same.