SO if I am to understand your story correctly
You did not!! Likely my writing skills threw you of track so I'll give it an other run.
Bull was heading down hill and the shot was down hill but not super steep. The bull was not running full out but moving and at the shot the bullet going over his spine and breaking the top of a couple vertebra stunned him and his momentum caused him to endo. Quickly he was on his front end paddling down hill in the bottom and he was trying to get his back end under him and another shooter who was closer shot him in the neck. His spine was not broken hence the ability to move out again and to try to get his back end under himself, he was not mortally wounded as no vital organ had been permanently impacted and given enough time he may have fully recovered.
Three years ago my buddy took a cow that was moving fine and looked good but when we cut her she had been hit exactly the same and had healed up none the worse. She was missing the tops of two vertebra and had holes in the tips of the shoulders that had healed over.
The first shot was not all luck but there was a good share of it there, he lead correctly for speed and it was his first shot so some amount of skill was involved. Second shooter was closer and his skill level is high, that shot was not difficult and the elk was not always moving so there was time to pick the shot!!
As far as shooting running elk, some days I go elk hunting and if they are running or I don't have the shot I'm looking for they win the game, they played better that day and they live, other days it's about body count and putting pounds in the freezer and they better turn the afterburners on if they intend to live!! The areas I hunt if you don't learn to hit moving elk your going to be sitting on your thumbs till your needed to drag elk out
That wound is fairly common from that kind of bullet as it didn't hit anything very thick or hard just a flimsy area of a shoulder and some small bones on top of the spine. Cut a few hundred head of elk a year and you'll see it more than a few times!!
This wound did not result in an impact of the bullet to the spine, that's the point! You have to know your anatomy is my whole point and show guys just what it is that some think you need to shoot through to drop elk.
The bullet impacting the shoulder blade does nothing to the spine!! I've watched time after time guys try to shot an elk in the shoulder with the wrong bullet and the bullet piles up 100% of the available energy on that shoulder blade and the only thing it does to an elk is make it run on three legs. Myth Busters busted the whole bullet imparting knock down energy, they couldn't knock a stiff pig of a beam at point blank range with an pile of different rifles. Your bullet hits to small of an area to fast to impart enough movement to kill an animal.
Another example would be a moo cow, I've hit a cow so hard with a post in the shoulder that it made her take a step to the side and she did not drop dead. If shoot an elk it won't be pushed at all unless your shooting an extreme class of weapon.
The "Knuckle Head" has likely killed more elk than most have seen, this was a new bullet and it obviously did not work and it will not be used again. If he shot elk behind the shoulder most times it would be GTG but for shooting bone it has to much frontal area without much behind it. I frankly do NOT care what a bullet does on the off side it's what it does on the on side and the middle!!!
The second pic is of the one from the shoulder blade to the leg bone, I believe it's the Humerus in a human. The big joint forms the point of the shoulder and is hella hard to punch through consistently but you see people saying shoot them at the point of the shoulder.
The only reason I brought up and arrow is I ideally place my first shot the same place I would an arrow, that's it's only relevance to this thread. The thread title is a little miss leading, I will shoot an elk through the shoulder but now I really only take it when I need to as a follow up shot, did it this year and the bullet did great and blew through and smoked it but I had already put a lethal shot on it with a smaller cal.
I think I about covered it all, sorry for the broken nature of how it's written. Oh, almost forgot, I don't think elk are anything other than big, tasty vermin. I've seen them devastate whole hay crops that I worked my @ss of to raise and I shot them like vermin when I could and coyote sucks, tough and stringy and I'll put a bullet through him while running as well!!