> But that doesn't necessarily mean that the law should try to perfectly reflect that moral imperative.
Indeed, which is why such laws should and are aimed at road safety.
> the more arbitrary and ambiguous the law becomes
"When you hit a pedestrian with a car, you're in the wrong", it doesn't become more unambiguous than that.
> do you drop the requirement of presumption of innocence?
That's framing the debate. If you hit someone with your car, you're guilty of hitting someone with your car. There is no "presumption of innocence".
> So you are creating a lot of ambiguity in the law in an effort to precisely match the moral outcome.
No. No ambiguity, and no matching moral outcomes, but improving road safety.
> in AZ, the law is a little more clear, but at the expense of not being as morally precise.
But it's not more clear, and moral precision in not a goal.
> It's a reasonable trade off.
Here I should draw up the statistics of accidents involving cars and pedestrians in Arizona and Germany, but I don't think that's necessary.
> It may suffer from an abstract moral critique,
> but I'm not sure on balance it delivers less justice.
That's just an incredibly U.S. centered point of view. I don't mind but your parent was talking about the German system. Maybe AZ works in comparison to the laws in other states with a very car-centered way-of-life, but in comparison to Germany it's really just bat-shit insane if the goal is improving road safety, but granted, that might not be the case.