The back story here is that the US/CIA tipped off the Thai authorities regarding this flight.
The crew have been locked up for a couple of months but to be truthful they seem to have benefited from their loss of weight due to the Thai prison food.
They were very overweight when they first appeared in the papers a few months ago but now look fit and healthy.
The diplomats have done their job and the bottom line is that the crew and aircraft never entered Thailand staying as such on the international side and just re-fueling. I'm sure Thailand would not like one of their aircraft impounded in the former Russian states.
So they are going home but the Americans are very angry.
Now just imagine if this was a CIA aircraft impounded in Asia