As someone mentioned before, you have to be able to loose an arrow without notice, espetially hunting solitary boars, I always have an arrow on the string while snaking around the woods, they can appear out of nowere, and you have to be ready to make a moving shot, because they seldom stand still.
I couple of times I left my guard down, and boom, a beautifull boar appears from nowere, and of course that split second chance was gone before I could recover.
.....This is by no means a proof, but the hogs That I shot with selfbows hardly run away, a couple, after the arrow pass tru, kinda just stumble around and layed down in sigth,even shot as close as 10 yards,... all the ones shot with a glass bow took of in a hurry, making the trailing considerably harder.
Noise matters
Manny