A federal appellate court appeared split Monday morning as to whether former Justice Department attorney John Yoo could be sued for authorizing the torture of an American citizen.

Yoo’s attorney, Gibson, Dunn & Crutcher partner Miguel Estrada, told the three-judge panel that his client should enjoy immunity from such an action. But his opponent, Jonathan Freiman of Yale Law School’s Lowenstein International Human Rights Law Clinic, said someone must be held accountable.