i'm pretty sure in uk law that by paying the chap that "found" the phone, the bloke from gizmodo would be guilty of dealing in stolen goods.
and of course we don't know for certain if the phone was lost and found or just stolen from a drunk guys jacket.
having said that apple are being incredably heavy handed over it and i can't help thinking that they are turning into another heavy handed big corporation much like the microsoft that they used to ridicule. additionally the one thing you should never do in business is pick a fight with journalists, if this blows up into a major issue then there could be a backlash against apple by the media.
surely the better way of dealing with it would have been a nice unofficial agreement for gizmodo to hand it back, keep quiet and then let them have the exclusive first test of the final product at it's launch. afterall apple were lucky, imagine if it had been sold to a rival company or a company that does replica's in china