In my limited experience with hogs, they do not readily admit their own demise. The situation becomes more bleak when you blow the heart out of 'em and there is no blood trail.
This spring, I did exactly that...took out both lungs, heart and liver. That hog travelled a good 200 yards into the brush with no blood trail. Moderator Harry Humphries and good friend Hilton spent the better part of 2 hours in thick brush with me before we found it.
This summer, I witnessed a broadside hog shot from Mad Dog's 30.06 special loads literally blow the heart out of the far side of a hog leaving a cavity big enough to put a fist in. He, too, covered over 100 yards in a matter of seconds and it took us about 30 minutes to locate the little feller.
OTOH, Ashley Emerson tells us if a hog that he once took down, only to remove last year's .44 cal round from the neck on autopsy.