Cats shouldn't be outside. A human driver probably would have hit the cat, too. Heck, my neighbor in his F250 purposefully hits cats and brags about it.
The American fetish with locking cats indoors is extremely weird, and your neighbour sounds like a first class bellend (and the one who belongs in confinement, at best).
Those stats on “how free roaming pet cats harm the society” will be a tiny bit hard to believe for anyone who has spent more than a few hours in Istanbul.
Assuming the pet cat in Australia is the same pet cat in Europe.