The point isn't that its plausible (which it is), its that its the only story you would expect a driver who wasn't already confessing to negligence/manslaughter

The point isn't that its plausible (which it is), its that its the only story you would expect a driver who wasn't already confessing to negligence/manslaughter to say: irrespective of what actually happened. Because if he had seen her before hand (i.e. she didn't "come out of nowhere"), he would have presumably taken control, breaked, swerved, etc. We already know that the car appeared not to have done that, so the profession from the driver literally adds no further evidence, since that is exactly what we would expect every driver who mows down a pedestrian unwillingly to say...