Secretary Rumsfeld and General Myers
Their press conference seemed mainly to address what now looks a lot like a suicide bomber with stuff strapped to his belly at lunchtime in Mosul, but the press "demanded to know." His reaction to the accusations is news, so no one can be faulted.
Reuters (linked) seems to believe he looked "subdued." I think he looked saddened and busy, which are what one would think he would be.
What could have been done to prevent this bombing? Probably nothing, but let's ask Tom Kean and Lee Hamilton anyway.