Aiming for the heart sounds good except they don't have a cut out on their side for reference. When you are staring at a Cape at less than a safe distance with a stick in your hand it seriously changes your perspective. The reaction on impact you described is very typical for all animals that aren't at the bottom of the food chain, especially on stalked critters. The pain they feel is probably no more than they have on a mad run through the bush. There is no noise or physical shock associated with a rifle and the adrenelin rush is very diminished. A very large percentage of mortally wounded game shot with an arrow will go a much shorter distance than a similiarly rifle hit animal. Of the dangerous game I have taken none went farther than 100 yds.(Ele) most under 50 yds..
The lethality of a bow must never be underestimated. After 50 years of hunting and hundreds of animals taken there is no room for discussion about which is most effective. No I am not talking about a charging anything. That is where a Rifle is worth it's weight in gold.
That ought to stir up the S@#$.
Dan