Most of the time you won’t see any external damage on roadkill, unless the skin has been torn or it’s obviously been run over. One good hit on a deer and it’ll die from internal injuries. If you were to skin it, you’ll see the bruising/bleeding where it was hit.
If it’s still warm, only way to know if it’ll be any good for consumption, is to sling it up, slit it’s throat, and see if the blood runs out. If the blood runs out, it’s good, if not, it’s only good for a skin. Once the bloods out, gut it, and let it hang.
I’ve witnessed a few deer being butchered by my dad’s mate, along with preserving the skins. I never thought the skins were worth the effort it takes to preserve them properly, but they can make good floor mats.