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.
When paddling in beam seas, the stern the kayak tends to swing around to point downwind, also called bowcocking or weathercocking.) A rudder is a great advantage in these situations as it not only helps the boat stay on course but can be used to help get the kayak back on course.