I saw several articles mentioning (and some showing videos) how the Mohammed video was dubbed over. The actors said what they read from the script was completely different.
Furthermore, some US intelligence says that the people who killed Ambassador Stevens and others may have used the angry mob as a disguise. Or they may have intentionally shown the video to the people around them, then used that protest opportunity to strike. US intel kept saying the killers were really 'terrorists' not related to the upset Muslims.