I worked in EMS for fifteen years. The amount of damage a bullet does is really a question of how much energy is transferred. In order to transfer energy into tissue, obviously the bullet needs to make contact. Minimal contact means minimal energy transfer; at some point the bullet’s just going to shear off the tissue it brushes against and that’s that. It’s not like a video game where a glancing shot is going to send him spinning through the air like a top and rip his ear off. Especially because the ear can kinda wiggle freely, it’s a bit closer to just nicking a paper target.