So here is what I think was going on.
Polls in September 2012 showed the Presidential race neck and neck. Many media outlets were openly predicting a Romney victory. Obama had failed to garner public approval over the killing of a man claimed (but never proven) to be Osama bin Laden, mostly because of the manner in which the body was disposed of and the obvious faked photos leaked onto the internet.
Obama needed a publicity stunt.
A small team of "Al Qaeda" terrorists, or someone playing at being Al Qaeda terrorists, were supposed to enter the Consulate and take the Ambassador and his staff hostage. Obama would let the drama build for a few days, allowing the media to hype the story, then send in the SEAL teams to "rescue" the hostages, then campaign on how he did not let the situation turn into a repeat of the Iranian hostage crisis, which would have dovetailed with the Iran bashing (and Argo).
But the best laid plans of mice and men (and Candidates) gang aft agley, as they say. We know that the CIA operatives at the annex could hear the gunfire from the Consulate. Looking at the consulate through Google Earth, one sees heavily populated residential areas less than half a mile to the east and southwest, who no doubt heard the gunfire coming from the consulate as well. Given how quickly sympathetic protests erupted across the Middle East during this incident, it is clear that the region is an anti-American powder keg awaiting a spark, which Obama inadvertently provided with his staged terror attack.
The initial "Al Qaeda" (or reasonable facsimile thereof) was a small group, but were quickly joined by Libyans pouring in from adjoining neighborhoods. What was a planned and rehearsed operation to "kidnap" the Ambassador triggered a spontaneous riot with at least 200 participants on the ground, and spun out of control, leading to the deaths of the Ambassador and others.
Obama's carefully prepped operation to make himself look like a hero instantly turned in an epic fail.
The corporate media is reporting that there may be a new Congressional Select Committee to investigate Benghazi, which is government-speak for one more tax-funded attempt to polish the official lies.