If a marine can qualify at the marksman level, he shouldn't have any problems hitting a man sized target slowly moving away at a small angle at close range.
Most people are surprised at how small Dealey Plaza is and how short a shot it was in the grand scheme of rifle marksmanship. Photographs don't necessarily represent the scale, and conspiracy theorists exaggerate the supposed difficulty of the shot.
You appear to be rather naïve about how firearms operate.
And probably hoping his audience is similarly naive. But in order to pad out the Gish Gallop to epic proportions he has to invent a bunch of "impossible" things, whether they actually matter or not. It's only important if the reader believes it matters. Conspiracism is about marginalia, which naturally leads to the complaint, "What do you mean that's not important, of
course it's important!"
Does it matter for some reason?
It's just the aforementioned Gish Gallop of "holes." The list has to be as long as possible so that it looks like there's an endless series of "problems" with the conventional story. That means trumping up a bunch of them. "Better shot" in whose estimation? By what standard?
This kind of question is perfect conspiracy fodder because it seems rigorous until you reveal the assumption behind it. "Gee, it's
obvious this other thing should have been done instead," is the form of the hidden assumption. Well, no, you're just letting the author sneak his assumptions past you without letting you examine them.
And ultimately questions about "Why did this person do this?" can be debated endlessly without resolution, and the answer to them doesn't necessarily bear on the overall question. It's just distraction to keep the debate going and the conspiracy proponent relevant.
That long list what constitutes a valid test is just plain silly. It doesn't have to be that detailed to be valid.
That's one of the insidious fallacies of the recreationist approach -- the notion that a happenstance occurrence has to be reproduced in all discoverable detail in order to validly demonstrate whether it was possible.
If the goal of darts is to hit a bullseye, and I throw three darts and hit the bullseye on my last shot (i.e., achieve the goal), then how would another player of comparable skill be asked to duplicate my feat? Would he have to hit the bullseye on the third dart? Would the other two darts also have to land where mine did? Would he have to duplicate my arm and torso movements exactly? What if he hit the bullseye on the first dart -- would that satisfy the objective of duplicating my feat?
It's a lot harder to duplicate the first thrower's
performance (including all the intervening happenstance factors) than to duplicate his results.
Manipulating the conventional theory's supposed standard of proof, to raise it to an absurd height, is a pretty common tactic. It especially fails when the manipulation is so blatant. Of course it also fails for the epistemological reason that no such arbitrary standard exists in order for some theory to be rationally the most credible of all its peers.