You were asking if anyone has had it happen.....I already stated that I saw it happen with a revolver dropping muzzle first onto concrete. So there is that......You said that bigngreens only argument was that it didn't seem safe, which is untrue. He stated (and it has been visually proven in this thread) that the fireing pin in a bolt action rifle IS resting on the primer with a certain (but relatively small, depending on the firing pin spring) amount of pressure, just like an old style revolver. The weight of the fireing pin/hammers of an old style fixed firing pin revolver and a modern bolt rifle probably aren't much different. I saw it happen with a revolver, and the same mechanics are involved with a bolt rifle in state C. It CAN happen under the right circumstances.
You stated if it dropped muzzle first that would likely be a safe direction for it. Well yes, if it is on soft dirt. But do you want to have a 140 grain going 37,000 fps out of a Creedmoore (there, I said it!!!) fragmenting onto a rock or richocheting within feet of yourself or someone else? I don't.
As far as what it takes for a negligent discharge to happen in C vs B, or numbers of occurrences, of course there will be more in state B because there are about 14 times (according to THIS poll) more people that choose to carry in option B vs C, so of course you won't hear about as many, which we don't hear about many in the first place.
Can a rifle in option B be dropped, bumped off saftey, then have the trigger pulled by a branch or be bumped hard enough to set it off? Yes. Can a rifle in option C be dropped and have enough inertia to set it off? Yes. I'm not going to try to change your or anyone else's mind, I doubt some random guy on the internet you don't know will ever change the way you manage firearm saftey, and that is fine. I have had one negligent discharge in my life, with a lever action rifle trying to de-cock the hammer, and it slipped off my thumb and sent a 190 grain hornady into the dirt. I was by myself, and following all other saftey rules thank goodness, nothing living nor any property was damaged, accept maybe my boxers, which may or may not have been soiled ha ha. I will never forget it, as someone that takes pride in my firearms discipline that was a hard hit to my ego. Everyone can make mistakes. I'm just saying, don't get a false confidence in method C. It is not any better than method B. Accidents can still happen.