Information gleaned may or may not be valid till checked out. There is no guarantee that the information will be wrong.
The effort must still be made by the torturer. To do nothing would be less moral by a long shot.
You keep making that very bad argument. It is the equivalent to saying that if you prove ‘Darwinism’ false Creationism must by default be true. Not so. I have told you at least twice, that not torturing ≠ doing nothing. You have ignored this point over and over.