IF ?
She's the Sec of State, unless she can prove interference from higher up it's totally her failure.
She certainly should have to take full responsibility for everything at the State Dept. barring, as you say, interference from above.
But 0bama missed his chance at being clean on this when he and his flack Carney actively took up the task of helping promote the "video did it" story. He can no more excuse his ignorance of the truth by blaming Hillbilly than she can slough off blame on him.