How far away, how fast is it moving, how much hold over, how much lead etc. Calculations easily made in a split second.
When an animal is gut shot the gut pushes against enterence hole and exit hole thus for all intents and purposes sealing them. The only time rumen will be excreted is when the holes match up. This can be very infrequently and only a few drops. The hunter concludes a miss but the animal crawls away to suffer a lingering death.
If we are going to voice our disproval of high risk to wound shots, voice disproval for them all.
Sounds like the voice of experience. Myself, I prefer not to gut shoot, and I seldom take a running shot - although I have done so successfully on a handful of occasions. The first time was a broadside fox at 125 yards, the last time at a quartering warthog running flat out at 60 yards. Both were bang flops, and no animal I have shot running has escaped me. If you are unable to make a competent chest shot, you have no place even thinking about a head shot.
I like heavy for caliber bullets which expand to over three quarters of an inch and penetrate through and through. When a chest shot is made with this type of bullet the game does not go far.
I for one do not understand the logic which would entice a hunter to try to hit a 2" target which may result in a horrible wound if the bullet is off by 2" when there is an 18" target which if hit anywhere within that triangle will result in a humane kill.
When I am seal hunting I take head shots because it seems this is the only shot which prevents the seal from getting back down his hole. Seals unlike any other big game animals are pretty much stationary, but even so I would prefer a body shot - it just doesn't seem to work for them.
Sounds to me like at some time in your life you made a poor shot and it has bothered you ever since. That is good, because the experience is driving you to ensure that it does not happen again - you just came to the wrong conclusion is all.