Drop-and-grab ND's have nothing to do with the style of the gun you're using, and everything to do with the idiot thing you just did.

It's common practice, and handgun sporting events, to require competitors to leave dropped guns on the ground, and wait for an RSO to pick the gun up.

This is because when you go to pick up a gun, it's at an awkward angle. You'll be embarrassed and surprised, so you won't be paying attention to what you're doing. You'll be in a hurry. It's awful easy, in those circumstances, to slip your finger onto the trigger. And in your rush and surprise, your motor control goes to hell--it's very easy to end up squeezing the trigger.

Or worse, you can grab it as it's still falling.

So at shooting events, the RSO is expected to check to see that the line is safe, take a gander at the handgun to ensure nothing's inside the triggerguard, and then carefully pick up the weapon, keeping the muzzle downrange, before unloading it and handing it to the guy that dropped it.

You hear a lot about guns going off when dropped because it's easier to say that than to admit that you were stupid and tried to grab it up. And people feel it's less incriminating.

In actual fact, I can't think of a modern firearm that isn't drop-safe by design. Revolvers, Glocks, 1911s in good working order--you could load them up and drop them all day (but don't).