In fact, this lesson had the same problems as the lessons I taught in tandem. Perhaps it would be pure fantasy to expect tandem teaching to increase the value of the lesson purely for the presence and perspective of the other teacher, but perhaps it should at least be possible to expect that the use of tandem instruction will not disrupt the lesson. The material that was discussed was not specific, so that each of the two teachers could not teach it individually, so even at this level, the lesson did not gain anything.
Perhaps it would be pure fantasy to expect tandem teaching to increase the value of the lesson purely for the presence and perspective of the other teacher, but perhaps it should at least be possible to expect that the use of tandem instruction will not disrupt the lesson.