I don't understand why this keeps coming up. I have never seen or even heard of a driver getting into a situation where there's any sort of moral dilemma in how they react. There's always an obvious best answer or a bunch of equivalently good answers.

For the one-in-a-trillion cases where this is not true, it's OK if the car reacts sub-optimally. It will still be vastly better than human drivers, who frequently react sub-optimally in unambiguous situations.