I'll concede to the point of "If the car had a good quality collision detection system, and the jackass did not deliberately disable it". You don't need "no manual input possible" for this. You just need a system smart enough to apply the brakes when the driver doesn't.

I was out car shopping recently, and even affordable midrange cars (Subaru Crossfire and Honda HRV) offer technology that could have done this, as a standard feature.