The original dust speck vs. torture problem isn't probabilistic. You're asked to choose whether to dust-speck 3^^^3 people, or to torture someone; not whether to do it to yourself.

If we reformulate it to apply to the person making the decision, we should be careful - the result may not be the same as for the original problem. For instance, it's not clear that making a single decision to dust-speck 3^^^3 people is the same as making 3^^^3 independent decisions to dust-speck each of them. (What do you do when the people disagree?)