The testing of a hacked-together system on the public road is not. He probably won't kill anyone, but if he were to I suspect he'd get the book thrown at him in the way that everyday death-by-DUI drivers don't.
Actually I'll go futher with this criticism: we've just seen drones being FAA regulated because users were unable to refrain from doing dangerous or nuisance things with them, such as flying near airports. DIY self-driving car research is similarly likely to damage the concept if it goes wrong.