Marty has been aware of DM's madness from the get-go, or shortly thereafter.
Why didn't he leave earlier?
Challenge's observation is not a fallacy at all. Marty has provided the evidence as to what he knew, and when he knew it.Complex Question Fallacy. Presumes a fact not in evidence.
Unless you possess great psychic powers or are God, you have no knowledge of when Marty Rathbun first became "aware of DM's madness" beyond what he may choose to say about that in public statements.
What Marty's says in public statements are admissions of what he knew, and when he knew it. How else are we supposed to know "when Marty Rathbun first became 'aware of DM's madness?'"
For example, in Factor 18, Marty writes that, "Miscavige has kept the international managers of Scientology in the lowest ethics conditions continuously for nearly two decades by imposing arbitrary requirements for upgrade nowhere covered in policy." That is clearly evidence that Marty has been aware of DM's "madness" for at least that period of time.
Even before that, in Factor 5, Marty writes that, "accomplished his coup by commandeering the only line of communication to Hubbard during the last five years of his life, plying Hubbard with embellished and false reports of a dangerous environment to keep him out of communication with Sea Org members and his family." Given that Hubbard died on January 24, 1986, this occurred from from approximately 1980 through 1985, almost 25 to 30 years ago.