Extreme but (hopefully) relevant counter-example: was the killing of tens of thousands of people (soldiers and civilians) by American citizens in Europe during World War II justified? This is a very complex question, and any reasonable answer will be even more complex and nuanced, so I'm not really asking anyone to directly answer it in this venue.
To be clear, I'm not talking about Tesla here, only the first sentence in your response, in isolation.
I think there are some circumstances where some deaths as payment for far fewer deaths that are morally and ethically sound and defensible.
If we can agree to that, then we can move on and analyze what Tesla is trying to do.
I'm not trying to invoke Godwin here: just that war happens be somewhat hard to compare - "people die, ergo same thing" seems a rather forced comparison.
Perhaps the only fitting parallel seems "history will be written by the victors."
But this is not a war in any way - there's already options in place to save lives - better policing, stricter speed limits, safer vehicles/roads/crossings. Allowing new technology on the road without the proper safeguards, (and the in my opinion abhorent justification that a few unlucky people might just get run over for the greater good) is not one of these options.
The "dangerous self driving cars on the road" option is only helping the pockets of Tesla's investors, not the public.
I think everyone wants better transportation and fewer deaths. But 0 deaths with an emerging driving technology sounds really hard. There are just so many edge cases and physics is pretty unforgiving on our bodies past 40mph.