Well then, you haven't.
I've always observed the damage of the bullets used on the animals we have hunted. It has always interested me since I was a kid.
In that occasion, the lungs were severely damaged. Now the deer didn't take off on a full sprint, it had some use of it's front legs and managed to cover some ground.
Bullet or shooter failure? Neither.
In a separate occasion, and I have mentioned this one here a time or two before. I put two Partitions on a coues, 2" apart behind the shoulder. Took a third shot to bring him down, bullets pretty much penciled through. Definitely shooter error. Partitions need hard muscle or bone to properly expand.