What he said, but I would take caustion intentionally targeting this area (you stated you weren't, this is more for later readers) because it gives a very small window of margin. For instance, if you had been aiming there, it would have been a total miss. Or even worse, if you were aiming just a little higher, it could have taken a chunk out of the elks back but not incapacitated it, leaving it to run off. If I want to anchor an animal in its tracks, and I am in a range and conditions that I consider optinal and can hit a small spot, I prefer to hit in a window about 2-3" tall depending on the animal, with the bottom of the spine being the top of the window, extending down 2-3". Even without directly hitting the spine, the hydrostatic shock temporarily (at least) parylizes the animal, and if the bullet performs properly, the lungs are destroyed as well, and the animal dies quickly.
If I do not feel comfortable on a shot with such a small window, but still know I can place it in the vitals, I aim top of lower third. Center body actually leaves less vital area above the POA vs below, where as top of lower third pretty closly splits the vitals (heart/lungs) in half. If I hit right where I aim, the animal generally does run, but if the bullet does its job, always less than 50 yards in my experience.