Last year during muzzleloader season I was hunting in a ground blind and I had to twist myself into a weird position to get a shot at a 6 point that was walking by. When I fired, the scope popped me in the nose and caused a trickle of blood to run down my honker, but I didn't even feel the pain due to the adrenaline rush.
I find that if scopes are mounted properly and are mounted far enough forward, there shouldn't be a risk of that happening.