I shipped an item the seller says was bad

I recived these connecting rods and didnt not need them. I sold them to a member and he was not happy with the packing job. I wrapped them in individual plastic bags and then put them in a flat rate box. Once the box had all the rods in it I filled the box with packing paper and sent it on its way. Seller recieved box and was unhappy about the packing. They were not packed extremly tight as I was at the limits of the Flat Rate Box. If this was wrong I appologize.