I keep shooting until they are down. Losing deer taught me this. My dad always says no no he's going down don't shoot again. WRONG. He's learning. If he's not down keep shooting. Shot a spike today at 50 yards broadside and knew he was down but he didn't drop and I sent another one through the lungs.
My thoughts as well, if it is still standing, shoot it again! A bit of wasted meat is not as bad as a lost animal.
This morning, I had a kid with me, I rattled in a buck, he shot, buck dropped, then got up, seemed to be teetering, paused for a minute then I told him to shoot it again, he missed, buck turned and started wobbling away, told him to shoot again, deer drops, gets up again, is teetering, we move a bit closer to get a better angle, shoot again, deer drops for good.
It turns out the first shot spined him but in the grass we could not tell that his hind end was dragging. we could easily have walked up to him, but given the same situation, I would have him shoot again and again.