We pulled an old green broadhead out of a buck when I was a kid in WI, he had apparently been fighting during the rut and another buck hit him pushing that broadhead the last 1/16 of an inch it needed to sever his spinal cord.
I've hit two elk in the spine, the first was my first ever shot at one, a cow at 10 yards. She stepped up out of the reprod and I drew back and let my instinct take over. Unfortunately, my instinct was still stuck in a treestand and I aimed high.... we saw her three days later, fortunately, with a big scabby stain on her but she was still with the herd. The second was an intentional neck shot as that was the only angle I had after putting an arrow in the back of one lung and the liver. I can still see that arrow, she turned her head away, I sat up in the grass, drew and let fly, it sailed perfectly, smacked her and head just dropped like a ton of bricks. Still not a shot I would take intentionally as a first one though.