If we put an AI in the role of the judge/attorneys, we will come up against "ah but the robot didn't do this thing that a human would do" and a lot of people would be convinced that the result was illegitimate. Not necessarily wrong, but without the legitimacy conferred by being done by a human being.
It would require our social system to turn over some decisions that have been done by a very protected sector of society (legal people) to newbies coming from the tech world. "This is the correct sentence because random forest says so" is going to ring hollow to a lot of people.