no, its not theft, its recovery of stolen property, if they are real, they are stolen goods.
Should be quite interesting to see it play out.
yet mentioned later in the article the the mint has already been forced to cave once
"but agreed after a lengthy court battle to allow one of the coins to be sold at auction in 2002 for $7.59 million - the highest price ever paid for a coin - after its owner agreed to split the proceeds with the Mint."