Her argument, made in testimony to the House Committee, is that it is the CIA's job is to conceal it's covert operatives identity and thus if the White House discloses an operatives identity, it is the CIA's fault.
I find this argument problematic, where the CIA has been so politicized over the past three years. That is, it is in the interest of the political appointments, at the CIA, to out Valarie Plame if they want to support the White House.
Toensing just said that the CIA did not tell the people in the White House that Valarie Plame was an operative. If this was the case, then why did the White House perceived leverage in outing Valarie Plame? That is, the fact that she was outed, to punish her husband, debunks the argument that the White House did not know she was covert.