Exactly. I'd expect collision-prevention to have absolute priority over any other system. It should not be possible for any logic bug or combination of environmental factors to make the car run into a large object in its field of vision. There's no need for statistics here--an overriding 'don't run into stuff' rule will suffice.
If there's truly no possible route to avoid some collision and therefore the car needs to decide which collision is preferred, then the statistics can kick in, but in this Uber scenario, it shouldn't have gotten that far. From the outside, it seems like a fundamental design issue.
> I'd expect collision-prevention to have absolute priority ..to [not] make the car run into a large object in its field of vision.
This is a good point.
But I think we've all placed our "toes over the curb" with a car hurtling towards us in preparation to cross the street as soon as the car has passed. No system can stop at each instance of this, nor can it recover past the point-of-no-return created each time this event occurs.
What constitutes "the curb" is subjective when it's not a raised sidewalk. Surely you don't have to be "on the grass" of a multilane high speed road but merely somewhere on the shoulder to claim expected pedestrian lane status. But that (may!) also imply you're an 'awaiting street crosser' not an 'engaged street crosser'. That's where the high level stats comes in.
The toes over the curb thing is a potential collision threat. It's fine to statistically categorize and prioritize these, as they're everywhere. But as soon as it becomes an imminent threat (i.e. is directly in the vehicle's path), avoiding the collision should immediately become the overriding objective. If the collision is truly unavoidable (this should very rarely be the case with an AV), then it should still be slamming on the breaks and doing everything possible to lessen the force of the impact.
If there's truly no possible route to avoid some collision and therefore the car needs to decide which collision is preferred, then the statistics can kick in, but in this Uber scenario, it shouldn't have gotten that far. From the outside, it seems like a fundamental design issue.