Hmmm.
I could actually buy the argument about the creature having been a pest - I remember there was an episode of Louis Theroux in which he travelled to a SA hunting reserve.
The guy running the place finally lost his rag with Louis and said "I shrecking *hate* elephants," and proceeded to tell Louis why, reasons similar to what's been stated above. To Theroux's credit, he included in the program a later discussion with a local vet, who, quite un-prompted, described how deeply the SA dude actually cared about his animals.
That said, do I really think the fellow in the present story was out there trying to do good for the local environment and economy? Like hell. He was out there to boost his ego and the perceived size of his wedding tackle. One for the underdog in that case.
I remember we had a similar, and similarly-heated, thread in here once before about some woman who'd killed an elephant with a crossbow. Apparently her wedding tackle was just as big as the boys'. I can just see it now, she got downwind of the herd, snuck around them, crept up on one of the elephants and killed it instantly with a bolt. (Or, no, she didn't - she actually sat inside a pre-prepared hide at a water hole, shot the critter when it wandered up then waited for it to die slowly, before posing in front of it with her fetching pink crossbow and newly-enlarged johnson.) ptui!