Did Obama and his subordinates make mistakes in the aftermath? Undoubtedly. They should have said less, and what they did say should have made it clear that information was still coming in. They should have admitted uncertainty and caution, never mind that uncertainty doesn't play well in the middle of a reelection campaign. Those missteps may have harmed the president politically, and did lead to confusion among the US public at large. But is it relevant to the efforts to find the killers, and to address the security missteps that left the US operation in Benghazi so vulnerable? No.
Joshua Foust wrote a good piece on all this for PBS yesterday that places blame on the Obama people where it appropriately belongs and points out that the so-called political "narrative" in DC is missing the boat. He points out that real damage is being done by the notion that intelligence uncertainty was some kind of crime.
The (intelligence community) is now absorbing the blame for the public misconception about the attack. President Obama was briefed by the CIA each morning for the first week proceeding that the attack was a spontaneous protest. It has since come to light that a CIA cable suggested otherwise immediately after the assault and administration critics have publicly accused the President of concealing information about the attack. Even some administration officials have placed blame on the intelligence community itself for not being clear enough about what happened.