As an aside, please note that all this article really states is that the attorney representing Langbord claims that the Mint cannot "prove" the coins are stolen. Well, that's for the court to decide. The knee-jerk reactions on this thread are astounding.
So if you're a king of Egypt the mint doesn't "seize" the coins, just splits the profits, but if you're an American citizen then those coins belong to the Mint.
The government has already allowed others who have the coins to sell them (including, apparently, her father). What's the difference now?