Humans certainly are imperfect and make mistakes, but will iterate with the understanding that doing nothing at all and blocking emergency vehicles is untenable.
At the least we will fall back to incentive/disincentive social behavior. People will supply ample friendly and unfriendly advice to try to unwind the knot.
Waymo should lose their operating license based on this experience. It's self-evidently dangerous to everyone to be incapable of basic iteration. There's a whole set of law driver's are supposed to follow for handling failed traffic lights. Why have lower expectations of an anonymous car than a human?