You're right, she did.
You guys must have seen a different video than I did. I saw this part of the debate live, and to me she came across like Tony Soprano's reaction to being slapped and told he's a fat, ugly homo.
No, I just tried to watch it through the eyes of somebody who doesn't already loathe her. The particular clip that was linked here made her sound much less shrill, somewhat (superficially) responsible, and the split-screen view made Edwards look like a prissy little nitwit -- which made Hillary! look much more adult.
She didn't come across badly at all in the clip -- I think opinions to the contrary are just FReepers projecting their own opinion of her.