I don't think shooting at running deer is inhuman atoll. If you know your capabuilities, and don't want to risk a shot you're unsure of, don't shoot. But there are many people, like Art mentioned, who don't even hesitate to take a shot that, to them, may be an easy one.
First deer I ever saw my dad shoot was a tall, wide, 3pt muledeer. We came over a ridge, and he immidiately came busting out of some brush, and was headed for the horizen, and fast. My dad (carrying his .270) pulled up, and just as the deer took his last jump on the rim of the horizen his gun went off. The last thing we saw was his back legs kick strait up toward the sky, and he dropped out of sight. My dad turned to us, smiled and said "hope he din't break his horns, cuz he hit HARD!" The bulletcaught him in the ribs, and he was kinda headed angled away and traveled up through the neck. We skined all the way to the head and didn't find an exit. He was bleading alot out of his mought, and was in a large pool of blood. The shot was at about 100yrds, running fast. I didn't even have time to get my gun off my shoulder, I was soo amazed at what happened. I guess it depends on experience though. Today my gun is unslung like greazed lightning
, but I dunno if I could get off a shot that quick. That takes years of practice.
PS. Back in the day (like our grandparents, or maybe some of your parents, or even some of you, who lived through the depression,) any shot was a good shot, because if you didn't connect, you didn't eat. My grandma used to tell us about "shooting red-tail hawks." I guess when you're hungry, anything goes.