I think the thugs conducted a “Snatch” raid on the mission in Benghazi to get the Ambassador. They wanted to trade the Ambassador for those prisoners at the CIA Annex.
The only thing we know for sure about the Ambassador is that he finished a meeting at 8:30pm. We see some photos of him being carried around by some young men. He was dead by the time the Americans got him back.
I think the thugs grabbed the Ambassador and then traded him for those prisoners. I think Obama traded for a dead man.
If the thugs have the Ambassador, what do they tell the CIA folks at the CIA Annex?
“If you try to rescue the Ambassador, we will kill him.”
I hate to give this administration an excuse, but it makes sense. They may have held back for fear of getting the Ambassador killed. Still not a good reason for not sending in the cavalry, though.