It just hit me that something was very wrong concerning the firing of the gun...Plus the struggle over the gun....the gun being in the holster so soon after it was fired.
Just a gut feeling.
The problem with your statement is that after firing no cartridge would be in the chamber if the slide was prevented from operating. Possibly the empty casing would be or it could have been ejected but the next cartridge in the magazine was not loaded.
The gun was reportedly found in the condition of having no live cartridge in the chamber and all remaining cartridges still in the magazine. That had to be due to incomplete cycling of the slide/bolt mechanism which can be the result of something interfering with its operation such as a hand on the slide or the barrel pushed up against an object ... such as a chest. More likely a hand on the slide. Pushing the barrel against an object can prevent a semi-auto pistol from firing at all.
Another problem with your terminology is that "discharge" means "fire" and a semi-auto does not and would not "automatically discharge" a round except for an extremely unlikely mechanical malfunction. That is not what has been reported to have happened. What seems to have been prevented, somehow, was the automatic re-loading of the chamber with a fresh round not a discharge.
As for the make or model of the gun virtually all semi-auto pistols operate in the same fashion regarding the issues described above.
That is just responsible gun handling and Zimmerman is said to have had four months law enforcement training with a sheriff's dept.
You don't carry a firearm, do you? There is no safer place for a handgun, especially when police will be arriving, than for it to be secured in a holster.
I would have to overcome my training to restore the weapon to operational status -- live round in chamber, not an empty case, if I knew this to be the case. Zimmerman appears to have either the presence of mind to leave the weapon as is (to bolster his case of self defense), or assumed it had it fact cycled fully. In any event all guns are treated as if they are