Compatibility issues can be sticky at times. I bought a piece from someone that worked in his rig but hummed like crazy in mine. I played around with the usual tweaks but to no avail. I told him about the problems & he offered a full refund including shipping - I was amazed but certainly gratified. A happy buyer meant more to him than $ from the sale did.
Having been treated so well in this situation I just wanted to mention it, but Jeff this is not your obligation of course. If you are inclined to make him whole, then have it shipped back to you on contingency that if inspection reveals no damage (scratches or electro-mechanical problems etc) then you would send him a refund less shipping. This isn't anyone's fault really, but it's absolutely your call. The buyers' story sounds reasonable enough.
Having been treated so well in this situation I just wanted to mention it, but Jeff this is not your obligation of course. If you are inclined to make him whole, then have it shipped back to you on contingency that if inspection reveals no damage (scratches or electro-mechanical problems etc) then you would send him a refund less shipping. This isn't anyone's fault really, but it's absolutely your call. The buyers' story sounds reasonable enough.