As for his ability to track a wounded deer, after hitting a deer with a crossbow bolt, or regular arrow, most hunters give the animal time to bleed out. After a hit, I normally wait at least an hour before I get out of my stand to go look for blood trail. Maybe he was going to do the same, and in that hour, call a friend to help him track it and drag it out.
Where I come from it is common practice to wait at least an hour if the animal does not drop in sight. Not waiting is considered a major mistake. If the animal drops in sight, we still wait some time just in case it gets up. So there would be plenty of time to get assistance.
The article mentioned hunting from an ATV, I'm not clear on if he was actually hunting from it, or using it to get to his stand or blind. Sue, you were wondering how he would handle a deer. If he got one, he may have planned on using the ATV to drag it back to the hunt club, or perhaps use a winch on the ATV to hang it to clean it there. Hard to say. Maybe he had a radio or cell to call a hunting buddy to help him drag it out.
That is issue is not just for paraplegics. Around here we hunt for wild boar. They may have 50 lbs or 200 lbs in weight. The small ones - or none at all

- can easily be handled alone. The big ones may well be beyond the physical limits of individual hunters. So we just arrange a way to get assistance when required. If you need it, you call else you donīt. There is no reason to assume the hapless hunter did not have arrangements. Frankly I would not expect that kind of information to appear it an article that focuses on the accident.