Credit card companies require that customers attempt to remedy any complaints with the merchant directly prior to initiating a charge-back. The customer clearly made no claim as to their concerns regarding the product, they just said they weren't the one that bought it, based on the claim of a fraudulent charge.

I see this much like purchasing a home. You have the opportunity to inspect the home during the closing (read code review). This is designed to provide a certification as to the quality of code without making the closed source code visible to you directly. If you don't utilize this, and the app complies as the same app that exists in the app store, it is hard to make the argument that you didn't know what you were getting. Unlike your example, as an app buyer you have the opportunity to use the app prior to purchasing ownership of the asset, so there is much more transparency than in a traditional app store software download example.