A source familiar with the matter confirmed Ron's exit, and added that he wasn't involved in Uber's self-driving unit.

Ron had founded Otto's autonomous trucking business alongside Anthony Levandowski, who has been at the heart of a Waymo lawsuit accusing Levandowski and Uber of stealing trade secrets to build its driverless car system.

Whatever the reasons, Uber is facing particularly close scrutiny that would put heat on Ron and other leaders. There are fresh concerns that a decision to reduce the number of sensors on Uber's test vehicles created blind spots. Also, it doesn't have nearly as much real-world testing experience as rivals like Waymo. Those factors might not have contributed to the crash, but they certainly haven't helped Uber's case in light of the Arizona tragedy.