Really? Guess you never any of the 500 or so posts on this forum alone quoting that precise requirement of the California Codes chapter and verse. Of course, if you pass the found item by, and take no action with respect to it that infringes on the legal possessor's rights, then you have no duty to investigate or to take any other action to return it to its rightful owner. Once you start picking it up, taking it out of its case, taking it apart, and taking photos of it, you have crossed the line, and since you did not take reasonable and just steps to reunite the phone with its owner before you exercised dominion and control over it, you are a thief. As a matter of fact, Gizmodo, by simply buying the phone, is likely guilty as a receiver of stolen goods rather than as a thief. Maybe that is cold comfort, but it's something, and following your diabolically clever plan would have put them in a worse legal position, not better.
The law is not so easily circumvented.
You'll notice, by the way, if you read this thread, that those admitting to being lawyers are all saying that based on the reported facts, the finder/seller is a thief under California law, and that Gizmodo is a receiver of stolen goods. You'll notice that those arguing that no crime was committed are all devoid of any credentials or experience with the criminal law of California. Perhaps you may find this fact relevant when you seek to form a reasoned opinion.