Because that argument has been repeatedly proven false. How would you know that the defendant was telling the truth? If your torture is working, then by definit

Because that argument has been repeatedly proven false. How would you know that the defendant was telling the truth? If your torture is working, then by definition the victim is in a rather confused mental state. SO even if you, as the devil, can assert that your victim actually has the knowledge (itself a difficult thing to know), how can you trust what is said under torture? Secondly, the argument is essentially utilitarian, "one person's rights in exchange for thousands"-- which you would argue was true in this one case. However, if your strategy was adopted as policy, how many torture cases would there be? Would it only be this one time? Or are we talking about thousands of people being tortured over the years in the hope that one time this save thousands of lives.