After watching an elk that was lifeless for long enough for a buddy to smoke a cigarette, load up the packs, hike 300 yards on the way to it through a small drainage, only to have the elk awaken from the dead when I slipped on some rocks about 50 yards away, get up, turn around and crest a hill… I will (and have) always shoot multiple times, even if they are “down”. That was an eye opening experience. It was laying head down, front leg stretched out straight down hill, with its tongue hanging out for easily 30 minutes. It looked dead as any other dead animal I’ve seen. But it wasn’t.
I've had the funny opposite. We kept shooting a barbary one time thinking it was still alive, but its head was propped against a rock making it look alive and alert.