No. Taking possession of lost property creates a "bailment", a legal relationship between the possessor and the owner, governed by local bailment laws. The offense by Gizmodo, if any, would be failure to report found property. It would not be espionage, since Gizmodo had no contractual obligation to maintain secrecy, and since Apple failed to take due care not to abandon the secret in a public place.

Assuming the story is truthful. If Gizmodo paid for misappropriation of trade secrets by an Apple employee, they are toast.