The best way to make Obama sound coherent and convincing is to give him a script. In this case, though, you can tell he just doesn’t care very much about the murder of the American ambassador and three of his staff in Benghazi.
Seems he’s more concerned to apologise for someone in the States exercising their right to free speech. As did the US Embassy in Cairo (which was also attacked):
The Embassy of the United States in Cairo condemns the continuing efforts by misguided individuals to hurt the religious feelings of Muslims – as we condemn efforts to offend believers of all religions. Today, the 11th anniversary of the September 11, 2001 terrorist attacks on the United States, Americans are honoring our patriots and those who serve our nation as the fitting response to the enemies of democracy. Respect for religious beliefs is a cornerstone of American democracy. We firmly reject the actions by those who abuse the universal right of free speech to hurt the religious beliefs of others