Niehenke, you have a point. My stands are usually only 12 - 18' off the ground. Some guys like to get way too high. Which is fine. But they forget that the higher you are you actually need to have the deer farther out to make a good shot. Too steep an angle and you very likely will hit only one lung. A killing shot, granted. But one where the animal needs time to expire.
And this is where the second error comes in to play. Following up too soon. I've learned from experience to wait at least one full hour before following up on what I believe was a perfect shot. Anything less, minimum of 2 hours, sometimes 4 or even the next morning if its going to be a cool night.
If you can't resist the temptation to follow, leave the area completely. Go have breakfast, lunch, a cup of coffee - whatever. Come back later. IF the animal is dead, he's not going to go anywhere. If not, you need to give it time to lay up and expire if you didn't double lung or heart shoot it.