So Apple loses this thing that's worth a lot to them. Critical "trade secrets". He tries to return it, they don't say anything. He could give the super-valuable thing he recovered back to him for free, but why should he? What obligation does he have to work for Apple for free?
Instead, he decided to cash in. Seems reasonable to me.
He didn't give it to the establishment he found it at. He didn't even contact the bar to see if the owner has been around to claim it.
He knew the full name and Facebook profile of the owner, based on the app on the phone before it was bricked. No attempt was made to contact this guy, despite the fact that he's dead simple to find on LinkedIn, Facebook (!), Twitter, etc.
He didn't turn it into any sort of law enforcement or other lost and found service.
What did he do? He called a few numbers where it's practically guaranteed people wouldn't believe he had a prototype iPhone. Any avenue where the phone had a reasonable chance of being actually returned was ignored. This looks highly suspicious. I would argue he is legally culpable for the phone's theft (but IANAL), but in either case I do not think this guy can claim that he tried to return the phone in good faith.
It's fundamentally the same as the classic "found wallet". If it isn't claimed, it reverts to "finders keepers". So I have no idea why people are voting you down.
Instead, he decided to cash in. Seems reasonable to me.