I have seen on more than one occasion a misapplied attempt at auto-forwarding (which is an intentional attempt to create a malfunction that the pistol is not designed for) which caused the slide going forward before the magazine was fully seated. The end result was a seated magazine, a released slide, and an empty chamber.
But that's none of my business. You roll your way, I'll roll mine . . .
In tens of thousands of auto forwards I have caused purposely on reloading many different pistols I have not experienced what you claim to have seen.
Because pistols with unadjusted slide stops will not reliably auto forward, or allow thumbing downward of the slide stop in many instances,
the overhand sling method is the most universally reliable way of getting a slide stop to release. I know and use this release method regularly, as should everyone. Using it primarily has many advantages, but there are potentially challenges associated with it, especially on smaller pistols, when using gloves, having only one hand available, etc. Using this one method is no guarantee it will always work to get a reload accomplished. Having one's slide stop set up to work with many slide release methods is more advantageous than not.
I would appreciate an explanation of how the "malfunction" you describe is possible.
The contact of the base of the mag with bottom of the grip is what causes the slide stop to "auto" release through inertia. The slide stop return spring helps with this action. Since the loaded mag is inserted all the way into the grip before the slide stop releases and the slide comes forward, in my experience the slide will always chamber the top round.
If the mag is not inserted all the way into the grip, the slide stop will not have released the slide--there has been no application of inertia to drop the stop.
If the slide came forward before the mag was seated, missing the top round for chambering, and yet the mag was then seated, what released the slide stop? Did the user prematurely thumb the stop down? That would be a user induced error, not a problem with the auto forward operation. The same user error, i.e., releasing the slide stop manually before having inserted the magazine properly, would foul any reload.
Intentionally causing the slide stop to release by subjecting it to inertia is no more a malfunction than causing the stop to release by pulling back on the slide or thumbing the stop down. It's simply a user controlled mechanical action that is one way to reload an empty, slide locked back pistol. When practiced with a gun set up to do it, I find it as reliable as any other method, but much faster. If the slide does not come forward, as with any unexpected lack of function, one trains to go to plan B to get the slide closed.
Concerning terminology, what is that button on the left side of the grip of most pistols right behind the trigger guard? It's primary mechanical function is to lock a magazine into the grip without any manipulation by the user.
After it has performed this task, it has an external tab that the user must depress to release the magazine from the grip. It is called a magazine
release, but it could not perform this function if it had not first locked the mag into the grip.
So shouldn't it be called a magazine
stop, since that is its primary function, just like the slide
stop?
See the similarity to the slide stop in function yet the difference in nomenclature? Nomenclature is far less important than function. Both these mechanical devices function similarly yet are described with different terminology. Why? Who cares!? It's the FUNCTION we are concerned with. They both BOTH stop AND release. They both require some user manipulation and some spring assistance.
Would you adjust your mag release to operate easier if it was so tight in its channel that you could not depress the external button all the way with your right thumb like on the M&P full size I just bought?
Adjusting the mechanical functions of your pistols is not taboo when done correctly and with a justifiable reason for improving the pistol's performance. Availing oneself of a variety of slide stop/release methods is good pistolcraft. There is nothing wrong with not making such an adjustment, and admittedly most people don't, but it does reduce options that some day may be critically advantageous. Training on multiple methods of slide stop releasing is a good thing.