If I may throw my own 2 cents in and get back to the original topic, I fail to see any point in which the writer 'submitted' to the TKD instructor. He acted as uke, yes, but is being uke being submissive? I don't believe so, especially not in this case.
In the story, Sensei Dan took the TKD instructor's wrist and began to teach him an Aikido technique, using himself as uke. Far from an act of submission, it is quite the opposite: He established and maintained the role of instructor in the situation, placing the TKD inst. firmly in the role of student. He did it in a very skillful manner too; in such a way that TKD couldn't object and had no reason to. An excellent demonstration of the first rule of teaching: 'control your class'. I have to remember that technique and add it to my repertoire.