"In that context, it sounds ridiculous. Yet in Brazilian jiu-jitsu, this climate is quite common."
I find the above statement appalling, and I can scarcely bring myself to accept that it is common. I've never experienced firsthand the close-minded jealous-ex-girlfriend instructor mentality, and I haven't heard any direct accounts of it from close friends. Of course, I began grappling as a Midwestern wrestler, where the mentality is to achieve victory at any cost whatsoever. My jiu-jitsu journey has been overseen by Eddie from the beginning, so it was never even a question that I would be free to go train with Josh Barnett or Jeff Glover or whoever the hell else could improve my effectiveness qua grappling. Eddie appreciates when his students learn effective techniques from other schools; he knows that we all grow stronger as a result.
In fact, the only way I can begin to understand the factious nature of BJJ is to invert your analogy, recalling the occasionally territorial nature of some of my academic interactions. I once had a famous professor stand up at one of my talks and say, "I will never believe X," where X was merely an observation and not my interpretation (we'd all die of boredom (myself included) before I could finish adequately explaining X, so we'll ignore the details). Rejection of an observation is anathematic to the scientific method, and yet dogma persists even in that community.
It saddens me that we cannot, as a species, allow free thought and open discourse not just in BJJ and science, but across all spheres of human interaction. If you can find the holes in my ideas and my techniques, then by all means point them out to my competitors; if I ignore my own fallibility, how will progress toward the unattainable goal of perfection?
From a literary perspective, I thought you would go a completely different direction with the palimpsest device. To me a palimpsest connotes a failed attempt at revision. It represents the ineptitude of the censor, the inability of the powers-that-be to extinguish troublesome ideas. Try to scrape away the traces of the past as you might, they're still discernible beneath whatever bullshit you've scribbled on top. In the same way, the jealous instructor cannot long disavow the effective techniques of a rival school, at least not without looking foolish. Perhaps this is why he feels so cuckolded by a departing student; his dogmatism is revealed for the disability it truly is.