The biggest issue for the wide deployment of autonomous cars is the legal liability for stuff like this, where it’s obvious that a human was unlikely to make this mistake. The robot can make human mistakes, but it can’t make robot mistakes.
If Waymo et al can successfully limit payouts to that, they'll be fine.
OTOH, if every death or serious injury comes with a 9 figure+ punitive damage award, they'll be in trouble.
I think states that nudge but don't completely require insurance have it right (I live near one of them). Even though most people have insurance the plausible threat of having to actually litigate against someone and attempt to collect seems to put huge downward pressure on everything saving even the insured people a ton of money more than offsetting the "risk" of sharing a state with uninsured people. Having laughably low minimums is the next best thing.