If your lawyer...
...tells you you should take a gun he hands you and go kill the guy in the gas station, and that it is perfectly legal... I'm sorry, the question is whether the law is broken, not whether someone gave you bad advice on the law. Muk also seems to be making the legal ruling that waterboarding has not ever been cruel and unusual punishment which is a task for a judge. Certainly we are bound by multiple international agreements not to torture.