accidents a 'fact of life' in Cali-fornicate-you
traffic accidents are a 'fact of life' in Cali-fornicate-you. You stop in the right turn lane and wait for pedestrians, someone looking left for oncoming traffic slams into you from behind. I suspect that's what happened.
And then there's the T bone incident. When the light is yellow, of COURSE I hit the gas to make it through. And if some idiot making a left turn tries to turn into oncoming traffic, well you just have to dodge them trying. The fact is you can wait until the light is RED to make your left turn, and since you're already in the intersection, just complete it when nobody's coming.
Those are rules easily programmed into computers, but POORLY programmed into driver's heads, especially when distracted by daily events, music, "new, shiny", children, and not even considering cell phones nor texting.
SO... maybe you just have to ASSUME that there will be accidents, and take a look at the causes, remedies, and what a human might do to avoid them, as well as the overall accident RATE.
But one accident shutting down the program? In Cali-fornicate-you CITY TRAFFIC? I doubt you could find a human capable of meeting a 'no accident' standard in those conditions. So why expect it from bots?
Another thing they might consider - paint the self-driving cars with highly visible colors [day/dusk/night] just in case the "silver car" wasn't seen at around sunset or something... (not knowing what color it was, just guessing possibilities).