It's possible but it's a fact that the face and lower jaw is the most common impact zone on your head. And it's also a fact that the DOT standard to which half helmets are tested to (because they absolutely can't pass any tougher standard) allows enough force to be transmitted to the head to kill you. They're better than nothing but please get a proper, preferably ECE rated helmet. I have a 6D and honestly believe it's objectively, and by some margin the safest helmet on the market, but anything with MIPS will not only save your life it'll prevent traumatic brain injuries. There's a lot of things that can happen to your head between "dead" and "normal", and a good helmet can not only keep you alive but keep your from drooling on yourself for the rest of your life.