That's not how it works. Imagine you had a medical device that had a high rate of operator-error that would result in serious injury or death. Now imagine someone made a fully automatic device performing the same function, but which would kill or injure a person half the time a manual operator would. Would such a device be allowed on the market? Of course not. The first time a machine did any damage to a human it would be recalled and would disappear off the market, no matter how much better it is than a manually operated machine.

If an automatic car kills a person through software error(and I would argue it has already happened with Tesla) the public backlash will be severe, even if those errors happen much less often than human mistakes in manual cars.