The real world violates the real world constantly. Improbability in the real world is not impossible. It is the same in art.
A good story must makes sense in a way that the real world does not. Some true stories have been scaled back a bit because it was felt that audiences would not believe them (e.g.,
Hacksaw Ridge).
A film must present the audience with a functioning Rube-Goldberg machine. If it turns out that it was the Col. Mustard in the study with the lamp stick, then when we reflect on what we've been shown the clues had better be there to not only reveal that this was possible, but actually "fitting." Life falls under no such requirement. If it turns out our universe is a false-vacuum and that the whole universe is collapsing the speed of light, we will never know.
Indeed, some fictions attempt to provide explanations for happened in life's mysteries (e.g,. Star Trek TNG explains that Amelia Earheart was abducted by aliens), providing the closure that the real-world refuses us.
Your hypotheticals exclude in-film explanations and ad populum fallacies aren't particularly persuasive on the use of the word. Just because a creationist says "that's just a theory" doesn't mean they have a grasp of the scientific meaning of the term.
But suppose the hypothetical were actual. Would you say that Thelma and Louise 2 has a plot hole? Moreover, we have an actual example from The Rodent. Is that a plot hole or just bad writing? It is possible, after all, however implausible, that the swimming pools would happen to be built where no graves were to be found at any shallow depth.
Again, I understand the impulse to police boundaries to prevent mischief, but we should not let such an impulse unfairly rule out borderline cases in which what happens is not logically, or physically, or biologically impossible, but so implausible in terms of events as we know them that, for all practical purposes, reasonable viewers conclude that that could not or should not have happened.
Perhaps we can visit these ideas at a later time.