Cracked glass/ Mcintosh

I don't have any experience dealing with an A-gon customer who claims the glass is cracked on a Mac integrated I sold him. I provided pics to him and the Mac was boxed the same way I got it from Mcintosh. Box in a box with it attached to the plywood. I find this very hard to believe.

What I'm wondering is how should this have been handled by the buyer. Shouldn't he be taking this up with the carrier? Btw, it was shipped on April 21 and just today he sends me the e-mail.The box was delivered 4/24 or 4/25. I'm just now finding this out. I also had sent e-mails to him asking if he got the tracking number and there was no response. Last week I sent an e-mail asking if he got the Mac and in both cases he never sent a reply of any kind. I need a little guidance on this.

Thanks to all
The quality, amount and length of time the buyer has garnered feedback, and the same criterion observed from those who left feedback for the buyer might be insightful.
I would want to know why there was the delay in his responding and advising. Maybe he got it, excited, slid it in the rack, rocked out for 10 days and then his audiophile buddy came by to check it out and pointed out the crack to him. You need to discuss all your reservations with him. If he can overcome them, I may be more willing to consider his claim.
An alternative would be to locate a company that specializes in plexiglass products - a new cover should be easy for them to fabricrate, cost far less and last longer than factory ordered. You could also split the costs.
Classic Audio Loudspeakers used to be called Classic Audio Reproductions, and did things like replacement glass for Macs. If its an older Mac you might check with him (John Wolff).