His lawyers are probably waiting for court to use it. Or, they are putting pressure on the State Dept. to sneak him out in the dark of night.
DSK did not travel on official IMF business to NY. He was on personal business, to visit his daughter who is a grad stiludent at Columbia.
The IMF has already thrown him under the bus. They have stated he was not on official business and cannot claim immunity under some UN agreement. He is not a Diplomat, does not represent France, and has no immunity.
If he did, do you think he’d be sitting in a cell at Riker’s?