Presumably one would compare Google's fully autonomous prototype against Tesla's fully autonomous prototype, not what Tesla is shipping now.

Given that Google doesn't have a car you can buy I think the jury is still very much out on who is ahead and behind here.

Tesla will have 100,000 prototypes being trained in shadow mode for a billion miles per year across the globe within a year. Tesla will compare quite favorably

Tesla models equipped with Autopilot enhancements do in fact have some form of emergency braking (automatic emergency breaking) to avoid rear-end collisions and primitive auto-steer.