I disagree with advocates of hump and Texas heart shots.
The only moose I ever lost was shot in the hump. If you do not get to them immediately and put in a finisher, they can get up and leave. All you have done is knock them off their feet and caused a wound that will kill them slowly and painfully from infection.
And as far as shooting a moose in the rear just so you can later put in a finishing shot, that's just bad manners. Nobody who isn't starving needs to shoot a moose that badly. Heart/Lung shots or CNS shots for me please.
I tend to agree on the THS - never tried it myself, but some here have, and seem willing to use it again. As Quigley said - "never had much use for it - didn't say I couldn't". Or wouldn't, under the right circumstances.
The spine is quite large in the hump area, and the vertebrae boney processes above are larger there than elsewhere. If the bullet hits any of those, the moose will go down right there, and it makes for a fairly large knock-down area- assuming you are not a bit too high and slip the bullet between two of those boney spurs.... Even a very near miss to the spine will drop them, but as you say, there is some danger that it will only temporarily stun them. Either way, they are likely to stay down long enough to approach more closely, assuming the bullet went where it was needed, and at not too great a distance. Note I said "likely" , referring to the "near miss".
On any CNS shot (or other) the thing to do is rechamber immediately, put the safty on, and approach (if possible) with a clear field of fire, keeping your eyes on the critter at all times. Better yet, if someone is with you, one of you approaches the animal out of the line of fire, while the partner stands ready to shoot should the animal stand up again.
Moose don't necessarily die from gunshot wounds. A friend shot one in the neck once, it didn't even go all the way down, and bolted. They tracked it until they lost the trail. The next year he shot a look-alike several hundred yards away, and found his last-year's slug in the neck muscle when he butchered it out at home.
Another friend once showed me pictures and antlers of a moose he'd killed a few days before when it came in snorting and blowing snot to his calling up Wasilla way. One antler was deformed, and nearly all the ribs on one side had been broken - some in several places- and rehealed. The lung on that side was misshapen and grown into the rib cage, but apparently was at least once more still partially functional.
Even those big heavy multi-ton projectiles (locomotives) aren't sure killers, apparently.
I also once shot a yearling bull, broadside and running, at 35yards with a 12 ga. slug, trying for his spine behind the shoulder, since he was crossing the trail back to the boat at the time. It missed the spine low by less than a quarter inch, but neatly centered the big artery that runs back to the hind end, leaving about an eighth-inch of arterial wall on each side of the hole. Hit no bone, the slug never expanded much, and exited. He never even flinched, much less went down, ran about 100 yards, staggered, and fell over in mid-step, all bled out. A case of a near CNS hit not paralyzing the animal. I always wondered if a high-powered rifle bullet with its greater velocity would have produced a knock-down on that one.
My own rule of thumb is to take the first certainly lethal shot I can make with good recovery prospects. If offered a choice of placement under somewhat problematic recovery conditions, I'll take the one most certain of quickest recovery. If recovery prospects are certain, I want a good bleed out for best meat quality- double lungs or heart work nicely, as I stated before. I haven't seen that much difference in time to fall over between heart and double-lung placement- both depend on the same amount of blood loss, and dropping pressure.
It's a sliding scale.... Other's MMV.
