Serious brain injury. Hit to front with pretty hard slam to the back of the head on cement. Coup/contra coup, some start to quiver or stiffen with a simple conclusion but that looks permanent or terminal. The nose/mouth bleeding is also indicative of a severe bleed. To me, at least. Have to ct or mri and evaluate in ER. If he gets there. FAFO is real.From a medical perspective, what happened/is happening to the dude that got knocked down?