There are multiple unsupervised cars around now, it was only the 1 before earnings call (that went away), then a few days after earnings they came back and weren't followed by chase cars. There's a handful of videos over many days out there now if you want to watch any. The latest gaffe video I've seen is from last week where it drove into (edit: road closed) construction zone that wasn't blocked off.

I would still expect a difference between California and people like you and me using it.

My understanding is that in California, they've been told not to intervene unless necessary, but when someone like us is behind the steering wheel what we consider necessary is going to be different than what they've been told to consider necessary.

So we would likely intervene much sooner than the saftey driver in California, which would mean we were letting the car get into less situations we perceive to be dicey.

Now you have phantom braking.

Phantom braking is better than Wyle E. Coyoteing a wall.

and this time with no obvious cause.

Again, better than not braking because another sensor says there's nothing ahead. I would hope that flaky sensors is something that would cause the vehicle to show a "needs service" light or something. But, even without that, if your car is doing phantom braking, I'd hope you'd take it in.

But, consider your scenario without radar and with only a camera sensor. The vision system "can see the road is clear", and there's no radar sensor to tell it otherwise. Turns out the vision system is buggy, or the lens is broken, or the camera got knocked out of alignment, or whatever. Now it's claiming the road ahead is clear when in fact there's a train currently in the train crossing directly ahead. Boom, now you hit the train. I'd much prefer phantom breaking and having multiple sensors each trying to detect dangers ahead.