I wonder if this is a true story?

[JuST Peter]

A former Sergeant Major in the NZ Army took a new job as a high school teacher in South Auckland.
Just before the school year started, he injured his back.
He was required to wear a thin plaster cast around the upper part of his body.
Fortunately, the cast fit under his shirt and wasn't noticeable.
On the first day of class, he found himself assigned to the toughest students in the school.
The smart-aleck punks, having already heard the new teacher was a former Army NCO, were leery of him and he knew they would be testing his discipline in the classroom.
Walking confidently into the rowdy classroom, the new teacher opened the window wide and sat down at his desk.
When a strong breeze made his tie flap, he picked up a stapler and stapled the tie to his chest.
Dead silence...The rest of the year went very smoothly.

[Brock]

 

My Ex sister in law had a similarish experience.

She is a short girl, of irish extraction.

On the first day at a new school, the class was acting up (as they do) so she slammed her hand down on her desk and yelled for silence. The desk fell to pieces ( it was pretty rickety to start with) and the class was deadly silent.

When asked how she did that, her reply was " My Husband is a black belt Tai Kwon Do instructor.. (true) and left it at that. No further problems.. 

[Biggles]

The story always involves a plaster caste and tough teacher with blowing tie.
IIRC it's not always set in UnZud.
There's no doubt about the fact kids remember demos like that.
We have a reunion coming up for one of the schools I taught at. I posted to the Facebook page and one student posted that she remembers me (from 1979) as the teacher who climbed the wall.
I had reached the limit of my patience with a particular class and turned to the "green board" (as they were in that era) and pulled a chin-up from the top of it, in the context of being "driven up the wall".
You had to be there...