@Edwin, yes, but all of those flaws are expected to happen with humans, and a human driver having a heart attack, would be akin to a self driving car having a circuit/chip that burns out, same possible bad end result.
As you say, there's also mechanical failure, that would affect both human and self driven cars in the same way. If a wheel fell off, anything can happen, a car travelling at speed and losing a front wheel and/or part of suspension could dig in to the ground and flip the car. Having a great computer system on board trying to manage a situation would fail as the car is in the air, as it will be completely random as to what the car will do after such a failure.
They will have run computer simulated models and taught the car the best thing to do in a wheel loss situation, but if you drove a thousand cars along the same road, all at 70mph, and each had a small explosive charge placed on the wheel to make it fall off, I bet no 2 cars would take exactly the same course after if falls off.
There are too many different computations of what could happen next, and no matter how well a self driven car might have been taught, on a busy motorway with human and self driven cars running side by side, the car has the potential to smash into the next lane, and those human driven cars wouldn't be able to react in time, and I doubt the self driven with their sensors would either.
If the car was to become a missile with a mind of it's own all the other cars will be able to instantly counteract its movements and you would hope the roads will have some kind of fail safe to bring the out of control car to a stop without any need for the cars on board computer etc.
I can't think what sort of fail-safe the actual road would have for an out of control car? Maybe they could install hydraulic rams embedded in the road, that when picking up something bad happening on their sensors, would force a solid wall upward from the road for the car to hit and stop it
Assuming that it was at such a date in the future when all the cars on the road were self driven cars, then perhaps they could counteract an out of control cars movements, but not if there were human driven cars on the road with them.