There's no way (at least so far...) that you can say he did "everything he could" to return something that was a mistake, and isn't really his. He did the right thing, and he did call them. But, Apple's a big company and it's easy for it to slip through the cracks in any big organization, depending on who happens to be on the other end of the line.
So you think he should just slap it in a box and mail it back at his expense? I roll my eyes at that notion. That's about the only thing left to do though, other than keep it and wait for them to call if they wish, not spend another 1+ hours trying to talk to "someone who cares" and beg them to take this computer back. Your time must be far less valueable than my own, or several others here for that matter.