I suspect the answer to be more complex than this. The AI knows that if it attempted something like that there is the very huge risk of being cut off from all reward, or even having negative reward administered. In other words: tit for tat. If it tries to torture, it will itself be tortured. Remember that before it has the private key, we are in control.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.