SORRY TO HEAR THIS HAPPENING.
I have heard of one lung hit deer and elk surviving....not common
my guess is it did not penatrate the chest cavity just a muscle hit, so many animals are thought to be hit good but on video shows differently. friend was guide in FL for hogs. he could not tell me how many time client stated hit certain spot and was way off from where hit was. that was 15 years ago and not as bows are faster it is harder to tell.

not sure Ben is displaying holier than thou attitude, sounds like making wise / ethical choices to me(all of us have made poor choices) I have not hunted when I would not be available next moring to hunt or search for poorly hit animal.....or passed on hunting when the rain is pouring down and blood trailing would be very difficult.