I can't see the picture you posted, but believe it is the picture showing the dust cloud rising off the back of elephant's head, with rifle in full recoil and front foot of elephant about 6 feet from Dr. Heath. I have read several of his books and articles, and there is no doubt that very few modern folk have every had the dangerous game encounters he has dealt with - both with 2 footed and four footed types of critters, bearing teeth, claws, AK-47's and so on.
However, one of his published stories, about an experience he had, and it is similar in many ways to those by a certain Mr. Phil Shoemaker in Alaska, was about their "DO NOT QUIT" attitude during a dangerous encounter. Dr. Heath describes being charged simultaneously by three lionesses; he being armed with his Husqvarna 9.3x62 and his ever present service revolver. He began firing the rifle while stepping backwards - when the rifle was emptied and one old girl was still oncoming, he dropped the rifle, drew the revolver and continued firing, while stepping backwards. By his account, the last lioness finally fell and died on top of his rifle.