That is the beauty of technology: once we identify a problem we can do something about it and apply the fix to everything. While this is the type of case you can argue nobody would have expected before, once it happens you know and can setup lab situations where similar things happen and then figure out how best to respond over months of effort.

This is absolutely not a case nobody would have expected before? People end up under cars in accidents regularly. Imo any company that "found out" about this scenario through the cruise incident is guilty of gross negligence.

I'm sure all the bigger ones had looked at the possibility before, but it's only natural to revisit it when something horrible like this happens to a competitor.

I am sure that you don't generally start with this scenario - but I have to say again that this is a common thing. People end up under cars all the time (in accidents). There is just no way anyone should excuse any company for "not considering" this scenario if their cars are on roads. I'm sure it's hard! Other industries recognize corner cases where they need to design to avoid really ugly long tail outcomes and do so with ethical rigor. Most planes do not crash into the ocean and yet you are educated on how to escape in a water landing at the start of every flight.

Note that it's not just a pedestrian ending up under a car, but the whole situation of "other car knocks pedestrian into your path, which then ends up under your car".

It takes years to learn all the corner cases. Maybe it was thought of but they got some detail wrong. Maybe they didn't think about it.

The problem is that the world is full of near infinite permutations of situations that will continue to prove difficult for these technologies. A group of pigeons, to most human drivers, is identifiable from any approachable angle, in various weather and lighting conditions. To a computer, it has to be trained on all of that and consider the countless permutations - is that two pigeons in the rain in the dark? Is it 50 in broad daylight? Is it 12 cardboard cutouts? Our brains are incredibly good at parsing the world around us, and I’m not sure we’re even remotely close to that level of accuracy with self-driving cars, and that should worry people in cities where these are being rolled out.