If you go prone into that corner you can't die from headshots. Only explosives. Plus that's why I said semi invincible. If you want god mode then hack the game.
this glitch suck ass when ur out of the door way u cant kill him if ur really close to him u can kill him. if ur out of the door way shoot him in the head. then he wont be invincible anymore. throw grandes, and flash bangs at his head. that the weakness of the glitch.