They were supposed to kidnap Amb Stevens.
The arrangement was that we would then trade him for a buncha Gitmo detainees.
When a couple SpecOps guys showed up and did what they do, the would-be kidnapers assumed they’d been betrayed or set-up.
Curtains for Stevens.
You nailed it.
There is a semi-credible rumor that Stevens was to be kidnapped, then exchanged for the Blind Sheikh. Purportedly, the deal was cut between Obama and Morsi as a means of improving electoral prospects for the both of them.
I think they were supposed to exchange Amb. Stevens for the Blind Sheik or whoever was the mastermind of 9-11.