Rich,
I never said that the coin got out LEGALLY. However, the issuance of an export license for the coin significantly clouds the legal issue.
http://www.coinresource.com/guide/exhibit/DoubleEagle1933.htm
Here, I'll even quote the relevant section...
"In early 1944, prior to the government’s discovery of the missing 1933 Double Eagles, the Royal Legation of Egypt presented a 1933 Twenty Dollar Double Eagle to the Treasury Department, seeking a license to export the coin to Egypt for King Farouk’s collection. The export license was required for virtually all gold coins under the extensive gold restrictions that had been in effect since March of 1933. Not yet recognizing the significance of an unissued 1933 coin, the Department of the Treasury inadvertently issued the export license and the King Farouk specimen was exported out of the United States."
The Treasury department has, in its own writings and statements, numerous times indicated that it was a mistake that this coin was authorized for export.
In fact, here, take a look at the U.S. Mint's website, starting in the entries for February 23, 1944:
http://www.usmint.gov/auction/index.cfm?flash=yes&action=theTimeline
By issuing the export license a single coin, it's possible (not certain, but possible) that the lawsuit brought by the dealer in 1996 could have been successful based on the claim that since the license had been issued, the coin was released by the government, and it had no further claim to that particular coin.
Between 1944 and 1996 numerous other 1933 Double Eagles were removed from private hands, including at least one that went to litigation (see Mint timeline entry for August 12, 1947, specific details unknown, I don't have acess to Lexis-Nexus).
It seems to be that no solid precedent exists that would have covered any court cases involving the King Farouk Double Eagle.
As I noted, the government legitimized, to some degree, the coin when it allowed the export license, even inadvertently, yet its actions in reclaiming others show a strong adherence to the claim that none of these coins is in circulation legally.