And if they had been allowed inside, what other next step could there possibly be other than something resembling a search? .
Note that this account is completely sourced from someone "on the inside" as it were:
“Someone came to [the finder's] house and knocked on his door,” the source told Wired.com, speaking on condition of anonymity because the case is under investigation by the police. A roommate answered, but wouldn’t let them in.
Everything that "source" says is a completely one sided series of defenses and trying to paint the seller/middleman as innocent good guys. The source here is either a future defendant or friend of the same.
I have no legal expertise, but I doubt our slacker will end up with anything other than a slap on the wrist.
But IMO he is nothing more than an opportunistic thief. Who took something that wasn't his, perhaps thinking free iPhone to play with and quickly figuring out a higher value was involved, so the hunt started for the best "fence".
There is ZERO innocent behavior here:
Starting with taking it away from the bar in the first place. This alone strikes me as wrong. Some rationalize this one, but to me he is clearly a guy looking to personally profit from someones loss from the beginning.
Next if you can somehow rationalize taking it as doing the right thing.

He did not leave contact information. WTF? Any argument about doing the right thing, falls apart here.
He never called the bar, to check if someone was looking for it.
Next he did not return it to either the person who left it, Apple, nor the Police. The Police was an easy one. No excuse at all unless this is someone looking to profit.
Finally there were the calls around to tech media with veiled payout requests.
IMO at the very least he should be fined the amount he profited from his sale of property that didn't belong to him after lifting it and making no honest effort to do the right thing.