In my writing I formulate this same concept differently (but congruently) and, years ago, gave it the label Bellwether Fallacy. For those without an extensive background in shepherding, the bellwether is the one sheep in the flock on which you put the bell, according to the principle that where the flock goes, so goes the bellwether.
The Bellwether Fallacy is the notion that a question to which a vast amount of evidence pertains can somehow be decided on the basis of a single "smoking-gun" bit of evidence. For example, the eyeball is allegedly the Bellwether point of Creationism, radiation is the Bellwether point of Moon-landing theorists, and things like the paraffin test are put forward as the Bellwether of the JFK case.
How it works is that the conspiracy theorist picks one point out of the vast realm of pertinent evidence, promotes it as an inescapable key point, and then pretends to debunk or expose it. Then, on the basis of that alleged smoking-gun failure, he declares the rest of the evidence to be irrelevant and thus it's unnecessary to examine it. So if the prevailing theory "must" fail by virtue of that one allegedly slam-dunk line of reasoning, and we thus "know" the prevailing theory is false, then the remainder of the evidence for the prevailing theory must "somehow" work itself out to also be fake or planted or otherwise nonprobative -- even if the conspiracy theorist can't or won't explain how. E.g., "We know the Apollo crew can't have survived the Van Allen belts, so I don't have to explain how we got the Moon rocks; it's obvious they were fabricated somehow because we know they really didn't go to the Moon."
The Bellwether Fallacy is really a composite of two classic Aristotelian fallacies: circular reasoning, and the fallacy of limited scope.
The fallacy of Limited Scope says that a hypothesis that explains or considers only part of the pertinent evidence is less likely to be true than one which explains more of it. It's frequently committed in the quest for parsimony, but committed also routinely by conspiracy theorists because their approach is almost always just to pick away at one thread or another, as you've noted. They havce to commit the Limited Scope fallacy because they don't have a credible alternate narrative from end to end.
Circular reasoning doesn't need much explanation among this group. It's simply presuming the conclusion is true for the purpose of establishing a premise that is circularly dependent upon it. Saying we don't have to consider other evidence for, say, Oswald's guilt in the shooting of Tippit because we know by some smoking-gun means that he was innocent (e.g., that Markham's testimony might be problematic), is the epitome of circular reasoning.
Of course the whole exercise is a strategy not to have to test either the prevailing theory or the conspiracy theory against all the evidence. Doing that would expose that the conspiracy theory really doesn't explain much of the evidence, or explain it any better.
That was me. It's a legal term and I used it in the context of a legal standard of proof. "Consilience" is a scientific term, and is far more appropriate to a wider discussion of the JFK evidence, or even in a pseudo-legal discussion of who, among all the available suspects, is the most likely to have killed Kennedy.
The interlocutors here have used the "devil is in the details" maxim incorrectly to assume that a conclusion drawn on the basis of consilience can and should be undone by some small outlying detail. Again, this is because conspiracy theories ever only pick away at outlying data points and never address the whole body of evidence.
so ma'am when I asked you if you recognised...
I misunderstood.