Buyer is claiming damage that was done by him!

Hi group,
I sold a pair of mint Harbeths. I shipped them in original double boxed carton with original bonnets covering them. I just received this EMAIL from the buyer. I know that many ruin these speakers trying to pry  the magnetic grills off incorrectly. What is my recourse with this issue?
Thanks  much for your input!

This is the EMAIL I received from the buyer!

Hi. I picked up the speakers from FedEx yesterday. They arrived with some minor dents around the front top corners near the grille on both speakers. When I opened the outer box, I've noticed that one side of the inner box wasn't sealed on top and as a result the speakers came out of the top foam speaker holder. I guess the damage occurred from speakers bumping against each other. The grill cloth is also ripped near the dents. I've sent an email to Harbeth asking how much replacement grills are going to cost. I could probably live with those dents but grills might be replaced at some point. I'm still waiting on my amp to come back from service, so I have not even plugged the speakers in yet. Hopefully the drivers are ok.