I think it's a bit more than unfair to invent scenarios from nowhere and then chastise people we don't even know for committing acts of our imagination.
Besides which, I know of no animal in North America which has a vital zone that would move 18 inches from "one step" and moving 18 inches in 0.8 seconds is a pretty good walking pace, hardly to be expected from a previously stationary animal in the time of bullet flight.
In any case, I suspect that the "DRTs" are a result of aiming for the high shoulder shot which has become popular. On a long range shot, it might be the safest aim too. High and you miss, low and you've got heart/lungs, forward and you've got neck and back you've still got plenty of lung/liver.
That elk shot, BTW, is
here.