The person found it in a bar. He made a lame attempt in returning the iPhone. He then sold it to Gizmodo. The moment he didn't go through the proper procedures when recovering lost property and sold it to Gizmodo, it became stolen property.
Yeah, I guess according to that 1872 California law. Especially if you know the original owner.
If they charge the seller, I hope he kept that $5,000 safe somewhere. He's gonna need it very soon to hire an attorney.