Then it seems to me that when responding to "Surely if BMR had claimed to be seeing law enforcement infiltration I would consider that evidence for infiltration, so how could I turn around and argue that lack of BMR claims was also evidence for infiltration?", you should lead off with "I would consider that evidence for infiltration, but against an imminent bust", before launching into all the explanation. That way, it would more clear whether you are denying the premise ("you'd consider that evidence for your thesis, too"), rather than just the conclusion. And the phrase "If a big market one expects" would a lot clearer with "that" between "market" and "one".