In this scenario, the student is a passive participant in the process. The information learned is impersonal. Clearly, the teacher is in control of the learning process; his or her interests dictate what and how fast the students learn.
The answer in all three cases is that rudder is used to help maintain stability in the roll. A little rudder at just the right time can help keep the nose up in a slow roll or even an aileron roll, as the plane rotates through the sideways portions of the roll when gravity is otherwise not countered.
Also, depending on adverse yaw, some rudder is required to hold yaw to zero when applying ailerons. The procedure is as follows: Speed up, so you are fast enough for roll maneuvering and inverted flight. Pitch up a few degrees. How much depends on wing incidence and zero-lift angle of attack.