A few of you touched on the point I got out of this, but no one explained it very well. In the first koan, Ougi says two things. The clearer one is tangential to rationality, but important for self-doubting cultists. “You are like a swordsman who keeps glancing away to see if anyone might be laughing at him”.
The more important point was that the teachings are valuable if they are useful. (This is applicable to the sword fighter because allowing yourself to be distracted is an immediate danger.)
The importance of the parable about hammers doesn’t relate to prices, but to usefulness. “Use the hammer to drive nails” in a discussion about rationality is metaphoric for using the techniques to make better decisions. If Ougi’s teachings help you make better decisions in your life, then they are valuable. If they merely bind you more tightly to Ougi, then you are a cultist.
Bouzo didn’t learn anything that helped him make decisions, he was merely cowed into following Ougi more closely. Ni no Tachi learned to “concentrate on a real-world question”, so “the worth … of his understanding [became] apparent.”
Ni no Tachi figured out how to use the hammer, but Bouzo only sold them without understanding their value.
“I should have paid more attention to that sensation of still feels a little forced.”
The force that you would have had to counter was the impetus to be polite. In order to boldly follow your models, you would have had to tell the person on the other end of the chat that you didn’t believe his friend. You could have less boldly held your tongue, but that wouldn’t have satisfied your drive to understand what was going on. Perhaps a compromise action would have been to point out the unlikelihood, (which you did: “they’d have hauled him off if there was the tiniest chance of serious trouble”), and ask for a report on the eventual outcome.
Given the constraints of politeness, I don’t know how you can do better. If you were talking to people who knew you better, and understood your viewpoint on rationality, you might expect to be forgiven for giving your bald assessment of the unlikeliness of the report.