Others (e.g., techcrunch.com) have said that they would have published about the iPhone prototype but not have paid for it. This wouldn't make any difference. The California statute includes buying, acquiring, POSSESSING, or Concealing stolen property a crime. Money need not have changed hands, at all.
There's a little room for flexibility here. Engadget published the finder's photos of it on 4-17 - apparently he sent photos to several media outlets in hope that one would reward him for it. Although it would have been more appropriate to forward any such communication to the police, if Gizmodo had got it, taken some pics or video that did not go any farther that what was already published, and then sent or brought it over to Apple HQ - the same county Jason Chen lives in - they could legitimately argue the $5000 was for the story of how the guy got it, the legal doctrine of prior restraint gave them the right to publish, and they had carried out their duty to reunite Apple with their property. And I think they'd have been legally and ethically OK.
It's the dissection, its publication, and the withholding of the device from its owners - even after they called to request its return - that has gotten them into real trouble.
