There is an option in
eBay for leaving a response to a buyer's negative feedback. I haven't had to use it (
) but I've seen it when I perused feedback for sellers I was thinking of purchasing from.
Guessing from the feedback I've seen here from your transactions, I'm betting that you did a terrific job, have beautiful eggs, and he's hoping for more eggs because of it. I'm also guessing that he's done it before, and had entire batches replaced at no charge. Makes me sad that people will do that.
I take photos religiously of all the packages I received... unopened showing any damage to the outside and documenting labels and flags, and then each step of the unpacking process so that IF there's a problem, I can show that it truly happened. I would think that anyone would do that. I'm even thinking of documenting my packing process, when I get to that point, to cover my butt, too. So far, all the eggs I've received have been packed like Fort Knox, and only time will tell whether they hatch or not...
You cannot please everyone all of the time. You've done all you can... until you hear back from the guy, don't sweat it. I know negative feedback is not desired, but if people only see one neg amongst all the positive, they have to be clued in that there was something going on.
Hang in there, take a deep breath, and smile... WE know it's not you.