It is good to discuss (thanks!), nothing is exact when it comes to safety as humans differ and every accident differs. Logical discussion of facts/likelihoods tries to provide rational approaches to keep irrational fears at bay. Most mountain bikers are very calculated especially when it comes to pushing the limits, and if you feel mentally confident in your safety set-up this goes a long away as well in executing the feature. I think this is why people chose half lids or full face, regardless if one if better. If they feel more confident, this goes a long way to being successful. Most accidents occur after the feature when you let your guard down.
I have a hypothesis with respect to the guys that go really big. They don't break like most humans. You see them crash and get up like nothing happened, whereas most people will break and stop. They are like rubber bands in many ways, and most of us are like potato chips.