Hello. I'm not one to say whether or not WR's experiment was "contrived" or not and am not taking sides, but am stating only that which I've personally observed and believe to be true.
Hammer-fired firearms do tend to impart more force to the firing pin. Examples that I've seen:
US Military .223, which has a "hard" primer to insure that the rare slam-fire from the M16, which has no firing pin spring, does not occur will occassionally not fire when being used in my bolt action .223, which has been utterly reliable with commercial and handloaded ammunition. Primed an empty case with one of the few CCI military primers I have and again, no ignition. Replace with a standard CCI small rifle primer and it goes. CCI primers even in their standard, civillian form are "harder" than Federal, Winchester, and Remington.
While shooting S&B .45 ACP ammunition, a buddie's Glock experienced a very, very small failure rate to fire the rounds, yet all of the rounds fired when shot from a 1911 that had a full power mainspring. One of the S&B rounds did NOT fire from either gun and didn't have much more than a scratch on it's very, very hard primer.
Also, I seem to recall some Greek ammunition a time back that was specifically not to be used in Glocks due to hard primers.
I am not knocking Glocks; there's a loaded G26 in my pocket right now, but I do not personally believe that they smack the primer as hard as a hammer-fired weapon.
Each and every weapon design has some "weak" point, but this never really needs to be one with the Glock. I've never seen a failure with a properly sprung Glock using commercial factory ammunition for defensive purposes and I 've fired so many handloads through mine with nary a stutter that while a failure to set off the primer CAN occur, it's very unlikely.
Best.