I can offer my opinion just as Dr.Curtis offered his. The title says 'tried to save' but the man stated JFK was already dead when he arrived at the hospital.
He's a medical professional, not a ballistics expert and is drawing conclusions that can easily be disputed. As I've said before in this thread many times the shots from the Book Depository were relatively straightforward from a rifle shooter's p.o.v, excepting of course the adrenaline rush anybody conducting an assassination must feel. I believe the FBI located the errant fourth shot much later and it wasn't in a curb it was through a road sign that later impacted the overpass.
I'm not a medical professional so I wouldn't dispute his findings in that area nor am I a ballistics expert. But probably unlike him I've fired tens of thousands of round of ammo and can state with perfect sincerity 'bullets do weird shit sometimes'. I've dug them out of earth and gravel berms and stacks of old magazines perfectly intact but for the rifling, I could probably reload them. Sometimes you simply find them laying right out in the open. It's not unusual to find ones right next to them utterly deformed - 'it all depends'. Sometimes there are ricochets that show up in unlikely places. One of the ranges at my pistol club had to have the ceiling covered in ballistic material for this reason.
Bodies, as deer hunters will tell you, can be relatively transparent to bullets depending on shot placement. You strike a heavy bone and the animal drops like a rock, or it doesn't and you're following a blood trail even if it was a well placed fatal wound. I am not a deer hunter but have shot plenty of small game with those results, I'm sure
@Rick Hunter could elaborate on this better.
Bullet design played a big factor here IMO. Remember the soft lead Minie balls from the Civil War era? Those things would shatter bone and cause hideous injuries as they were relatively slow heavy soft lead projectiles that expanded massively while still delivering considerable energy to the target. Hunters use lead soft tipped bullets with copper semi-jacketed cases to provide both penetration and expansion and even at that if they fail to strike bone can still pass through and through a target relatively intact should anyone care to go find them.
Full metal jacketed bullets like the military 'ball' ammo for either rifles or handguns, the same as the ones I've shot and witnessed many times myself and those Oswald used are not designed to expand at all. It's not considered humane to hunt with that ammo for that reason, at least around here or out in Wisconsin where my brother has hunted most of his life. I have no problem with the 'magic bullet' theory at all or JFK's reactions to being shot - as I said things don't alwaysgo as expected and sometimes 'weird shit happens'.