[SittinYonder]

After a legal battle, the dealer was permitted to sell the coin at auction on the condition he split the proceeds with the Mint.

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?

[1rudeboy]

If a cop lets you off with a warning, he is under no legal obligation to give you one again.

[newgeezer]

So if you're a king of Egypt the mint doesn't "seize" the coins

Actually, it's unclear whether the king or the coin dealer was in possession of that single coin. (Not that it matters.)

What's the difference now?

The government has not relinquished its rights to these 10 coins (there hasn't yet been a "legal battle" such as the one that resulted in that sale). If Langbord can hire the right lawyers, she might have a chance.

Again, if these 10 were originally obtained illegally, I'm thinking seizure is justified. If your lawyers can negotiate a deal, more power to you (and money to them, obviously).