I will be totaly honest and say I have shot deer at a walk with a rifle.

After carefully placing the shop the deer died instantly. I dont recomend any induvidual taking moving (being slowly walking) shots, unless you are completly secure and confident with the shot and your self.

In most every case I wait until I have a stop shot, but when I only have a short open window and I am totaly comfortable with the out come I will shoot.

As far as the show you watched where they bow hunting? Again..... If the person taking the shot was in any question of the quality of the shot or his abilities he should have waited.