Legal chalenges are this: the driverless EV ran over someone but what happens is that corporations (often) bribe the judicial parties not charging them with a hit & run even though the victims families want justice for their vehicles killing pedestrians. The only “prevention” is harm reduction (investing into technology that’s able to detect human presence & sensors that activate in pedestian heavy areas stopping the vehicle).
Usually, when it’s a EV (with no human driver behind the wheel): is it still considered a criminal offense if a driverless EV ran over somebody as it just continues driving? In that case it’s mainly rideshare companies (i.e. Uber, Lyft, DiDi, etc) face criminal liability. Regardless, the companies who dispatch EV’s are sued when their vehicles run over somebody and the EV didn’t stop whilst doing so.
OP is asking about an accident and responsibility, not a trolley problem.
You pretend AVs can’t make mistakes just face difficult choices. That’s false.
You also pretend AVs are safer than human drivers. Nobody knows if that’s true so let’s not pretend it is.
And even if they’re safer than drivers, someone (other than the victim, ideally) still needs to be responsible when they inevitably hit someone.