So, a 'perfect' shot with this rifle, would still be minimum 3 MOA off and 2.5" high, or up to 5.5" off the mark under benchrest conditions.
There are assumptions inherent in this analysis.
1. If we assume that LHO used the scope, then the analysis assumes that the scope/mount was misaligned PRIOR to the shooting.
LHO clearly discarded it after shooting; there's no reason to assume he would have handled it carefully after he was done with it. So it's reasonable to assume (or at least accept the possibility) that if the scope did get misaligned, it happened after the shooting, not before.
In addition, there's ample evidence to prove that LHO had practiced shooting this rifle in addition to his extensive dryfire practice. There's every reason to assume that if the scope was off prior to the shot he would have either known that and fixed it before the big day or simply not used the scope at all. And that's the second big assumption hidden in the analysis.
2. It assumes that LHO used the scope.
LHO could very well have used the iron sights. At least one reenactor ignored the scope and used the iron sights to duplicate the necessary hits under re-created conditions. The scope mount allowed the easy use of the iron sights without requiring the removal of the scope/mount.
A neck shot and headshot (2 for 3) with his skill, weapon, distance, and movement.
Again, this hides an inherent assumption. There is nothing to suggest that LHO was aiming for the head or neck (upper back, actually--it wasn't really a neck shot). Given that he missed entirely with one of his three shots, it's far more reasonable to assume that he was aiming COM (per his military training) for the exposed portion of JFK's body and that the two out of three bullets that connected happened to hit in the head and upper back.
First, the car was going 9-11 MPH. That's the average human in a full sprint speed. I doubt many people could score a headshot on a human in full sprint at 80 yards under the above conditions.
First of all, a human can sprint a good deal faster than 9-11mph. The record is nearly 28mph and the average, from the sources I can find is 12-15mph.
However, that's essentially irrelevant since the last shot was taken with the target moving nearly directly away from LHO's position. There was virtually no need to correct for the target motion. In other words, he missed one of the two shots taken when he would have needed to correct for motion (although much of the target motion during that timeframe was also directed away his position and therefore not an issue) and elevation and connected with the one that required the least correction for elevation and motion.
In addition, the analysis is still based on the idea that a headshot was what was intended--an assumption that can not be verified and isn't particularly likely to be correct given the point of impact of the other two rounds--one of which appears to have missed the entire vehicle.
Strange things happen in the real world. Some years ago, a DFW area LEO became frustrated after pursuing a fleeing criminal on foot and shot the top of the running felon's head off at about 70yards with a single shot from his issue service handgun. I'm sure he wished that someone could have proved that what he did was impossible since it cost him his job.
...he could not to the point that he would not have attempted the unlikely.
It takes very little study to establish that LHO made a habit of attempting the unlikely and doing the irrational.
Other tests show that it CAN be done. It also shows that there are a LOT of failures in trying to replicate it. It certainly is no guarantee.
One thing that's important to remember is that the re-creations are done assuming that the 2 out of 3 shots that did hit the target hit exactly where LHO intended them to hit. That's a much higher standard than would be imposed in the more likely scenario. If one looks at a shooting scenario where the shooter takes 3 shots and makes 2 hits on the scoring portion of the target and misses the entire backer board with the other shot, it's pretty unlikely that the 2 shots that did hit the scoring portion of the target hit exactly where the shooter meant for them to go, even if one hit in the X-Ring.
I absolutely do not believe that Oswald was capable of those shots with that weapon on that day. Why? Science and ballistics.
And those are the two best reasons to believe that he took the shots.
There have been numerous painstakingly detailed and high-fidelity recreations and analyses which demonstrate that the shots came from LHO's position.
Basically there's nothing in the evidence that proves he couldn't have, ample evidence to prove that it was possible and even more evidence to show that the shots came from his location.