If you look at the Libya section of the debate, you see the whole workings of American politics, and Candy Crowley might have unwittingly cracked it open.
Romney (and the entire American right wing) had concocted this idea that Obama/Clinton/Ambassador Rice had "bungled" the attack in Benghazi by waffling for those two weeks about whether it had been caused by an act of terror or by a protest over the movie gone awry. And they were right about the two-week interval: Ambassador Rice had referred to it as a protest and the president had as well, and they both said they were waiting for the "facts." Conservatives were able to weave this into their narrative that the president is "soft on" Islamist extremists.
But Romney, every commentator at Fox News and everyone right of center neglected to go back and listen to what the president had actually said immediately after, when he said the now famous phrase "no acts of terror." He didn't specifically say "this attack on our embassy was an act of terror," which they could have nailed him on if they were being accurate, but nevertheless, he referred to it as an act of terror, even if it was in the plural.
Had they been content to confine their criticism to the "two weeks of muddle" and not gone for the gold of the "label as terror" meme, Romney would have won the point at the debate. But, filled with hubris, the conservatives have been gloating inaccurately--a dangerous way to gloat!--that the president "refused" to label it terror.
And so, with her simple "Actually, he did," Candy Crowley, dealt a possibly fatal blow to the spin of the Republican Noise Machine.