A change in the vision system can absolutely affect handbrake tests. As far as we know, last week how Uber detects obstacles changed in a way that affected late

A change in the vision system can absolutely affect handbrake tests. As far as we know, last week how Uber detects obstacles changed in a way that affected latency enough that it couldn't brake in time, which is why we now have a broken person instead of a broken test. An autonomous car is inherently a system, and you need a deep suite of integration tests, regularly run and covering all possible cases, to believe you're even approaching vehicle safety. The wider you space out when any given integration test is run, the harder it becomes to fix. And if a given test only runs once per week, sooner or later (sooner with a sufficiently large test suite) you're going to hit a place where auto-reverting the commit breaks additional tests. And when that happens, unless you put a global lock on new code entering the system, it might be impossible to fix the regression. And putting a global lock on new code submission will make new feature development extremely slow and expensive.