Unfortunately some (people) think when the magazine is removed the gun is unloaded. Too bad when they turn it on their little brother and kill him. I don't know if that scenario had any thing to do with JMB's design feature.,
There are no safeties that fix carelessness or stupidity.
At one time I had command of the portion of our agency in which the armory was housed. We had completed about half of the transition from 357 revolvers to 5906s when the 9mm failed miserably to perform to expectations in each of the first 3 shootings in which an officer hit attackers center mass. Our new Chief listened to good advice, then simply exchanged remaining new 5906s for 4506s (and a few 4566s for agents/lts & above) with our vendor and exchanged 5906s for 4506s in the field with officers who had already transitioned. We completed transitioning with 4506s.
I was easily available at HQ, so it happened that one of the higher-ranking elite needed to turn in his 5906 and had already received his 4566. He came to my office to turn in his 5906, but I was elsewhere, so he left it (in the box) with my secretary, who gave to me on my return. It had one empty mag in the well, and the 2 extras in the box.
I removed the mag from the well, pulled back the slide, and out popped a 9mm super-duper hollowpoint. If the dunce had pulled the trigger (remember, the mag was in the well, rendering the mag safety irrelevant), the pistol would have said, "Bang." I took it all to my boss, who 'handled it' by unkown, unofficial means.
Often wondered if the Governor was ever told the head of his security detail wasn't careful with firearms.