In my early days as a Gliding Instructor I can remember teaching cable breaks (simulated by pulling the release cable!)...after the various demos and practice, we then told the students they can expect them at any time..and obviously without warning!
So the plan was to go back to circuit bashing and leave it a few launches to settle them back into circuits before commencing the 'fun' of pulling their first simulated cable break.
..however, on this day my Student obviously thought he would help and pulled his own on the very next launch! .... now as an instructor you should always be prepared for a cable break...but that caught me completely by surprise and I must admit I was chuckling to myself as (IIRC) he made an ok job of it.
....Lesson learned to make sure the Student knows and understands the rules in future!
A couple of years ago, as a lapsed glider pilot (but working professional pilot), I was flying with an instructor who had briefed me that on one of the two flights, we would have a winch launch failure. On flight one, as I transitioned into the climb there was an loud bang, which i took to being the instructor pulling the bung. I pulled the release 3 times, lowered the nose announced ‘cable break, landing ahead.’
The instructor chuckled and said ‘ okay, good.’
After we landed he explained that I had given myself the cable break, not him, and the bang was just the strop pulling straight. (Something new to me as a 80 hour glider pilot.) Anyway, he passed me on the launch failure part of the check flight!