Perhaps he prefers to bring up Etruscan, Phoenician, Assyrian, and Carthaginian treasures. I doubt that they have the lawyers needed to retrieve "their" sunken treasures.
Depends. The Arab government of Egypt is very protective of their antiquities -- stuff that predates the Arab-era in Egypt by thousands of years. It would be amusing if they weren't so darned aggressive about it.
Extrapolating on that, I could see the modern state of Libya getting fired up about Carthaginian artifacts. Same for Lebanon or Syria with the Phonecian stuff. Then of course you have the UN which just throws sand in the gears for everybody.