There is no "hole" for the target to fly in in 3 dimensions in a dynamic situation. But it is a traditional excuse that has some real use level so it cannot be discredited. Alternate facts have a long and illustrious history.
Wonko, have you looked at the photos in Brister's book? The ones of patterns shot at stationary targets vs moving targets? A 2D pattern--which you get when you fire at the traditional pattern plate or paper--is as good as it will ever get, because you've eliminated the 3rd dimension: time. A swarm of pellets doesn't fly through the air like a pie plate. It's more like a cone. And depending on distance and angle--the greater the distance and the closer to 90 degrees the angle, the more pronounced the effect--there will indeed be holes in a pattern shot at a moving target that aren't there when you shoot at a stationary target. Brister's photos of pattern sheets resulting from shots fired at moving targets demonstrate that very clearly.