I don't doubt Presschecks point at all.
A number of years ago I was involved in a fight with a bear. I had only a .44 revolver. The entire scene was total mayhem, with screaming of dogs, growling of bear, high speed movement of all involved. At one point in the fight I was mixed up with the bear at my feet and pushed the gun into its chest and fired what I thought were two rounds, then got the gun up to its head and pulled the trigger with nothing but a "CLICK-CLICK-CLICK-CLICK" being the result. As I tried to reload my then 13 or so year old son dove over my shoulder and more or less "bayoneted" the bear with his rifle, a 7x57R with a shot to its chest which finished the deal.
After the panting was over and we rehashed the whole affair he told me he distinctly heard what sounded like a 3-shot burst from our Stempel submachine gun when I fired into the chest of the bear.
What I "felt" and thought was "Boom-Boom" was actually "Boom-Boom-Boom".
I do not recall if I even heard the fast double action shots but if I did I certainly wasn't doing the simple math very well.
Like I said earlier, the whole issue is irrelevant unless you plan on shooting indoors regularly without hearing protection. My wife is pretty understanding of my gun nuttism, but even she takes a dim view of regular gunfire in the living room...