There’s clear evidence that a bullet did go past his ear. He was likely reacting to the noise of it. I wish I could find the video I saw but basically, you have to find the clip of the wide angle view. It’s not 100% evident that this is what caused the blood but it’s extremely compelling and just makes all the sense in the world. I’ll keep looking.
Found it! https://www.youtube.com/watch?v=4TOtnYboqxQ