>> If Tesla makes a mistake in their autopilot software, people might die.

In this case, a good "Testing on Production" rule would be to not let customers test your software, period.

There's plenty of land and resources to construct towns and cities that simulate real-life commute very accurately.

In the case of self-driving (or even autopilot), you're not really testing a feature, you're researching a new product, they difference is vast.