Someone managed to demonstrate just how P320s go off.
(Sorry if the Sig updates are getting old and annoying)
TLDW for anyone who doesn't have 40 minutes to get through it now, if the trigger is partially depressed (and by partially I mean <1mm) and the slide is manipulated (again by <1mm, about .5mm in this specific example) then the striker will drop and potentially discharge the round
Basically, if you have the tiniest bit of trash caught in your trigger mech or it's the tiniest bit out of spec and then wiggle the slide (such as walking around with it in the holster, he managed to get it to strike with a holstering motion as well) then it can go off. He was also able to get it to strike by partially inserting a magazine, just the magazine/cartridge pressing against the bottom of the closed slide was enough to trigger it
This is all with the upgraded trigger and no other modifications
Still watching, I haven't gotten to the part where he gets successful primer strikes, but obviously that happens as he opens the video with it, I'll add more if there's anything else super interesting, but even in the case of the striker safety successfully preventing a full strike then you'd be pulling a dead firearm out of your holster when you're expecting it to bang
Edits:
1: He hasn't been able to seat a magazine without setting off the striker while the trigger is partially (<1mm) depressed
2: 24:30 - He more or less managed to recreate the airforce fatality, just smacked his desk while the gun was sitting there and the striker dropped
3: Successful primer strike on literally the first try, striker safety seems to be intact
4: 5 for 5 on successful strikes, the safety didn't stop a single one
5: The video didn't really cover why this is happening, what exactly is going on inside the gun, just the how, and effortlessly repeated it dozens of times
Definitely worth skimming through the video just to see how little it takes to set the gun off in the right circumstances, but he doesn't explain much so don't feel like you need to sit through the whole thing