I don't need an excuse.
A commander and chief is ultimately responsible for the actions of those under his command. Plain and simple truth. Policy or not, if someone under his command breaks the law, do something unsavory, he is also to blame. After all if we didn't invade Iraq no US soldier would be a part of that prison scandal. It simply would not have happened.
It is however, policy to torture via the CIA. I think that such measure needs to be in place and we need to have strict guidelines on what is and is not torture.