Author here :) I cannot answer for Uber, but the grand reason why we cannot put deterministic parts into the AI is the same as for humans - we do not control the internals of it, the complexity is too high. Although we can build systems that are composed of both AI and deterministic collision avoidance (as seen on new cars today). It is what I also suggested in the article.
Ah, then I should complain to you that "AI" is a broad suite of techniques and goals, rather than a specific black-box technique which has these flaws.
Yes - you really seem to be talking about Machine Learning (a subset of AI). And as another comment says 'This makes me want to pull my hair out. No reasonable system relies on AI [or ML] from top to bottom. Take this article with a grain of salt, it is attacking a straw-man.'
