A lot of people seem to mention how LiDAR should have seen her coming: Generally speaking, that's true. But it's difficult. In a single frame the system would hopefully detect
something on the left of the lane, but wouldn't know what it is (if they use AI it's probably not trained for "person shoving bike packed with plastic bags").
If you have the object detection in place, you still need a trajectory for that object; if you don't know the exact angle you're looking at that object it's difficult. And moving at any speed there are plenty of things that could go wrong with the calculation, especially for slow objects.
Also remember you're seeing a lot of oncoming traffic (for which you don't want to do an emergency brake) and cross traffic moving onto the road, letting you pass before they enter your lane (for which you might want to slow down a bit).
Maybe the bags reflected LiDAR light causing a wrong classification... Maybe their detection noise was too high and the quick fix was to turn down sensitivity.
Whatever happened exactly (and I hope we get more information), this is a terrible accident, because the object in question was not part of some controlled test, but a human being left dead.
Still, the technology is very promising, but companies should be more careful with testing; have drivers be aware of the road (is that IR light from the camera or a smartphone?), and maybe do more testing in controlled environments.
As a software engineer, I would only release an autonomous car into the wild after I trust it enough to walk into its path on a dark road (with enough space to brake; suicides can not be avoided)... I wonder if the Uber engineers would?