Sure, you don't know how well any specific driver is going to react in an emergency situation, and some are going to be far worse than others (e.g. panicking, or not thinking quickly enough), but the human has the advantage of general intelligence and therefore NOT having to rely on having had practice at the specific circumstance they find themselves in.

A recent example - a few weeks ago I was following another car in making a turn down a side road, when suddenly that car stops dead (for no externally apparent reason), and starts backing up fast about to hit me. I immediately hit my horn and prepare to back up myself to get out of the way, since it was obvious to me - as a human - that they didn't realize I was there, and without intervention would hit me.

Driving away I watch the car in my rear view mirror and see it pull a U-turn to get back out of the side road, making it apparent why they had stopped before. I learned something, but of course the driverless car is incapable of learning, and certainly has no theory of mind, and would behave same as last time - good or bad - if something similar happened again.