Yes, it will be trivial to detect - once double-checking the address becomes part of the procedure for verifying package delivery. If checking the address isn't part of the procedure, then the procedure needs to be modified. Low-paid support people are expected to follow the procedure exactly, so that the company can obtain consistent results.

Unless there's something I'm unaware of, they have no way to check the actual shipping address based on the tracking number without direct cooperation from the shipper. The reason they use the shipping city is that most shippers provide that information about every tracking number. To get more information you have to be the one who shipped the package. In this case amazon was not the one who shipped the package. It was a 3rd party seller who shipped on their own.

In this particular case, the customer was able to get a proof of delivery from USPS which included the recipient's address. Amazon had both the customer's address and the address the package was delivered to, for some reason they just would not or could not notice that they didn't match.

I'd hope that checking the address would be part of the procedure for asserting that the package was delivered to the correct address. If not the first time through, it surely should at least be part of the appeal process.