I don't even think you have to appeal to people being old or children. The idea that a distracted human being is going to be able to take over for a machine with 360 degree vision in an emergency is absurd, no matter how able they are.
The case I was responding to was one of car breakdown. Of course the other case would be an emergency while the car is moving (which is what you are talking of) and here i think the evidence is compelling. To hand over control to a distracted driver at the worst possible moment is not likely to work well. It actually does not work well even for trained pilots, as the Air France crash some years ago showed.