Bad writing S6E24 Grey's Anatomy

Just not believable! You have two war vets doing nothing to get the killer. The killer is shot by SWAT and what, the SWAT guy does not close in to kill him?! No one is calling security early on and there is no speaker system for entire hospital?! Anyone who knows anything about a pistol, you move yry to get out of aim and distance, when its a pistol. Just dumb, No one Ducks, No one goes after shooter, just not believable.​