If you believe that the only or most likely explanation for the location of the head wound is that Brown charged the officer, during which he received five shots first, you're fucking crazy. End of discussion. We're not talking about some combatants in Vietnam dusted off angeldust and adrenaline shrugging off gun shots. MOST people under normal circumstances would be down after one shot, maybe two. Go watch some ISIS videos and see how people react to getting shot in the leg.
Worse yet, the pause in the audio makes the rhino charge alibi even more remote. What, Brown got hit a few times, paused like a turn based RPG, charged again, and was defeated by Wilson's final attack(s)? It doesn't make sense.