Just to share my experience on electronic devices...

Usually good product designers do vibration & shock tests on their product to see its durability... For shock test there might be some external damage on the device if it's not durable enough since it's done by releasing the device to fall from certain height, but for vibration test, the device is shaken like crazy and it's hold on tightly by vibration test machine thus even if there is no external damage there might be internal damage to the device due to the vibration that it has sustained (Modules disconnected, parts fell off, etc.)

- Similar to TS case, even if his body/thigh probably cushioned the phone during his fall, but there's still damaging impact to the phone internally even there's no damage outside.

- Similar to motorcyclist that crushed his brain during accident even though he was wearing a helmet

All I'm saying is, it's probably useless to prove that the phone should by right, work by displaying that externally it's still good.

Still, seller could've done more to help out... whatever happened to customer is always right? :-)