What if I choose not to pick up the product at the time we agreed upon without notifying you, causing you to make decisions about inventory and perhaps selling the product to someone else, and then return to you demanding the product at a later date?
He already paid for the product. In fact the delivery of the product came in 2 shipments.
For the first shipment he basically said to throw in the trash, now you as a business could throw it in the trash, or resell it since it's going to waste.
The customer was there for the second shipment yet you were not there to deliver.
Poor example. Implies you being forced to do things you would otherwise not have to do, which wasn't in the original example.
Better would be: If you rented me an apartment and I didn't move in right away. It would be unfair for me to demand a refund for the time I didn't move in, but it would also be unfair for you to rent the apartment to someone else if I already paid you for it.
Multiple leases I've signed had provisions about failure to take possession. If I didn't move in right away, or moved out early, I still owed the full rent for the lease period, but the owner could rent the place out to somebody else. (whether or not that's enforceable in a particular municipality is an entirely different matter)