Nothing wrong with it if it's done correctly. If you hit and kill a squirrel or a rabbit and have the know-how and the means to dress it, how is that any different from shooting one? A couple of states permit road kill salvaging. There is a push in MT to make it legal. Don't know if it passed.

Crossing the country we came upon a pheasant in ND that must have been very recently hit as the blood from its nose had not congealed or yet. A woman in the group remarked that she wished we had a way to transport it and prepare it for dinner. Instead, she plucked feather for a couple of us and we attached them to our bikes.