Are you saying that people intentionally strike reindeer with their automobiles?
That sounds far-fetched to me, but I could also see it as a form of dangerous poaching.
Erh What? You are obliged to kill an injured animal. So you just break a leg and remove all owner's markings, if nobody saw the accident.
Fur is €300 and canned meat is €10 / 100 grams. So 50 kilo reindeer is eventually worth over €5000.
People do it out of spite. We have similar problems with the white population hating the Sami similar to what USA has had with Indians. There were cases just outside of Umeå close to the winter rally where some raindeers were killed. [0]
The drivers feel that the Sami puts the reindeer on the road to be in the way and cash in on the money they get for the killed raindeers. (Secret tip: It's not enough to be worth it to watch your domestic animals die in your hands or be forced to finnish them off yourself because the owner are forced to take care of the dead animals.)
[0] https://swedenherald.com/article/three-reindeer-killed-linke...