I particularly appreciated this excerpt from your second example:
If you are right now deciding whether to back up through the concession because of the GRV for failing to execute correctly the Vendilion Clique ability, then you have missed the possibility that Player A may have cheated by intentionally failing to remind Player B to draw a card for the Clique. That issue needs to be resolved first because that determines the infraction.
I imagine many judges would jump straight down the GRV path, and I think this highlights a problem with our approach to training judges on policy. Many of the resources we use to teach judges how to apply policy to various scenarios explicitly tell us to assume from the outset that no cheating has occurred (see notably the Knowledge Pool). In essence, they presuppose that a sufficient investigation has already taken place, and that we are convinced no players involved were cheating, but they don't go into the details of how this conclusion was reached. It would be very beneficial if we could develop a scenario-oriented resource which focused on training judges how to investigate, and I think these three articles are an excellent start.
Thanks for the enjoyable and informative read, Eric!