Re: Reasonable defaults
Yes, but defining the correct criteria is hard.
Do you emergency brake when a bird swoops across the road? (it's close, so need to break hard to avoid it). A large bird may be a similar size to a ball that a child is about to chase onto the road
An attentive human is pretty good about making those decisions (we're built to recognise moving 3D objects) - so providing training data from human-controlled cars can help (video as input, and output of if the driver took action - even if too late)
Part of the problem is those cases are really rare - humans are good at noticing and remembering unusual things; but they make for sparse training data for AI
If it was been able to track the same "object" even though the classification had changed (as opposed to "There's a new bicycle there" "The bicycle is gone, there's a new unknown object"), then it could have kept the movement history and made better decisions