Doesn't this just suggest that computer vision is practically impossible to perfect, and that cameras + LIDAR would be far better for safely driving a car? You need actual distances to objects, not just fuzzy error-prone inferences.
On a more realistic level, stereoscopic vision seems like a pretty decent way to get distances.
Humans do pretty good with fuzzy notions of where the animal is. Exact distances aren't needed so much as reasonable estimates. If it is probably in the "need to brake zone" then the car brakes. Plus or minus a few meters isn't a big deal so long as you've got margins to work with. As animals are unpredictable, Volvo certainly has wide margins.
The things seem to be able to effortlessly execute 90 degree turns between hops, at speed.
Safety lesson: if you see kangaroos travelling alongside the road you're driving on, slow way down so you can execute an emergency stop, if needed; they're always only one hop from suddenly being right in front of you.
Safety lesson 2: there is always another kangaroo. If you see a kangaroo bound across the road ahead of you, slow way down; there's likely to be another kangaroo a very short distance behind it. (And safety lesson 2 recurses and also applies to that second kangaroo; there is likely a third kangaroo just far enough behind it that you'll think there's no third kangaroo. And so on.)
I'm not surprised they get hit as often as they do particularly at night.