The Exchange?

Al-Qaeda Terrorist Makes Explosive Benghazi Claim: Amb. Chris Stevens Given Lethal Injection After Kidnapping Went Bad | TheBlaze.com: "The “plan was based on abduction and exchange of high-level prisoners,” the terrorist wrote on the prominent jihadist Web forum Ansar al-Mujahideen Network. “However, the operation took another turn, for a reason God only knows, when one of the members of the jihadist cell improvised and followed Plan B.”

I don't think I had given enough credence to this possibility before. That may also explain the "we were sent by Dr. Morsi" video... RTWT.