Politics and Religion
It either has to be mob riot due to the video or a planned terrorist attack. It can't be both, or any combination of the two. It has to be black or white in order to fit into the attention and logic framework for many of those on the right. It's an old tactic, which you see often in movies and TV shows, where the defense attorney or the prosecuting attorney makes the witness answer in terms of 'yes or no,' when the attorney know quite well the neither answer reflects the full truth of the circumstances. 
Quote :
What he did in the period just before the attack has remained unclear. But Mr. Abu Khattala told other Libyans in private conversations during the night of the attack that he was moved to attack the diplomatic mission to take revenge for an insult to Islam in an American-made online video.
To now ....
As the attack in Benghazi was unfolding a few hours later, Mr. Abu Khattala told fellow Islamist fighters and others that the assault was retaliation for the same insulting video, according to people who heard him.
In an interview a few days later, he pointedly declined to say whether an offensive online video might indeed warrant the destruction of the diplomatic mission or the killing of the ambassador. “From a religious point of view, it is hard to say whether it is good or bad,” he said.
http://www.nytimes.com/2014/06/18/world/middleeast/apprehension-of-ahmed-abu-khattala-may-begin-to-answer-questions-on-assault.html?hp&_r=1
All of this is not new but from NY Times Oct 2012 and not once in that interview report did they mention that Khattala was upset about an online Islam movie.
http://www.nytimes.com/2012/10/19/world/africa/suspect-in-benghazi-attack-scoffs-at-us.html?pagewanted=all&_r=0