Tell me your joking! Has someone really ever done it this way so that the student has to throw the switch? I have never heard of that. That would have to be the most unsafe thing I have ever heard of if it is true. The student gets into trouble, and the instructor is yelling "throw the switch, throw the switch" and the student can't figure out what to do as the airplane flys into the pits. Man, that would be one instructor that should not be teaching. The student should always be on the second radio.