I doubt this is a description many people would agree with - that agency doesn't exist but we just pretend it does so we feel better about locking people up to modify their behaviour. Aside from anything else, if we are probabilistic systems, we presumably can't actually do things like rationalise, or design things like legal systems. Similarly, I'm not sure it makes sense to talk about the legal system as having a goal if it is a (presumably slightly more complex) probabilistic system.
Of course, just as with materialism we can bite the bullet and accept that our typical descriptions of human life are strictly false and the real story is just a scaled up version of billiard balls knocking each other around (mutatis mutandis for the probabilistic picture). But if we want a picture that lets us keep some of our current view of human life, it is not clear that bringing probabilistic systems into the picture helps any.