F.L. Whiteley wrote:

Statement: "You have control"
Response: "I have control"

I have known of an instructor and tow pilot flying together where no one was
in control and the glider exceeded VNe slightly in a dive and was recovered
gently once the situation was realized. It could have ended otherwise.

The instructors of my club were pretty hardcore with that "my controls /
your controls" thing. I would never have thought somebody would not do
so... until:

Until I got my introduction into mountain soaring. Not a club thing, so
the instructors were unknown to me. Once during a flight, the instructor
demonstrated something, I forgot what. Anyway, after the demonstration,
we flew along gently and quietly. After a while, he made a shallow turn
away from the mountain into the valley. "What is he doing?" I asked
myself, waiting for his explanation. He didn't explain anything, but
after a while, he suddenly asked: Why are you flying over the valley?
Turned out, neither of us had the controls, both thinking the other was
flying. So much for a well trimmed glider.

I've learnt that lesson.

Stefan