A few years ago I shot a nice buck but over estimated the distance. I thought he was like 25 yards but he was only 20. I hit about 3" under the top of the back straight in line with the vitals. We tracked and tracked. Put in at least 12 hours looking for the deer. Two months later I got a picture of him on a trail cam checking a scrape. It would have been my first buck and first deer with a bow. You could see the scar from where the arrow entered. I think there must be an area of no vitals or spine or anything there. I don't think people realize it until it's happened to them. By the way, two weeks after i hit that nice buck, i nailed a 5 pointer at 25 yards.