But you'd be surprised how many hunters will get pissed off at bad shots. Making a kill quick and clean is kinda part and parcel of serious hunters.
But you wouldn't strap a living deer onto your vehicle. You field dress any game you're taking home, even if it was trophy (though, fuck trophy hunting). You don't let the guts stay in place any longer than necessary, and you want the carcass to start cooling asap. That cooling goes faster when the internal organs aren't holding heat, and the insides are able to be cooled directly
Ain't no deer surviving field dressing.
Now, I was never a deer hunter. A lot of my family were, and were generous with the meat, so me taking down another one would have been pointless, wasteful, and that made me not willing to actually kill a deer. I used to have some great pictures I took from a stand though. But, I had no issues helping do the work necessary after someone else did.
You just wouldn't ever drag a deer to your car and strap it on without field dressing (aka gutting, for anyone not aware). It would likely taint part of the meat. And, again, it would slow cooling, so any meat not tainted by the breakdown of the guts could end up spoiling as well, in a worst case.