I'm sorry Hyacinth, but to criticise the mother for not supervising her child closely enough is blaming the victim. You should be able to trust your child to play on their driveway without having to stand right next to them in case a stray dog attacks. As for, "he could've just as well been run over", that is entirely the parent's judgement. I am rather sure that if she thought there was any chance that her child would disobey the "stay off the road" rule, she wouldn't have let him play there. I am not at all a fan of the current day expectation that you need to hover over your child all the time, just in case something really random and devastating might happen. Or for that matter, because people seem to think that you cannot give a child any responsibility over their own safety at all. It's a far cry from how I was brought up and there is no valid reason for this change of attitude.
Other than that: Cats rule, dogs drool! (I love droolers of course)