Apologies for missing this one. Remind me how old is your son again???
<<Yesterday there were 15.
A perfectly normal class size, for an adult instructor. Students on the floor are the O-N-L-Y priority, the teacher made a foolish mistake.
<<Chaos was an understatement.
Chaos is what we do... the ability to handle it well is the mark of the professional instructor versus something else. The wandering, water, bathroom, hug routines are relatively easy to adjust. He absolutely must keep and hold their attention for no more than 5 minutes.
<<No one wanted to co-operate.
What does that mean?
<<one of the mothers decided to complain about my sons poor teaching.
Something in particular? He is a fairly young man if memory serves... she had the wrong complaint.
<<oversized due to parents showing up un-announced.
Sigh, the instructor needs to be taught how to respond better. Even if that is/was the case, you cannot, cannot put it that way! It makes it seem that parents were the problem... noooo it was his hideous lack of adult staffing was the only issue. His response was "over her head" because that is not HER concern. She brought little Timmy in one of the time slots that was "acceptable". Not her or your sons fault many did so.
<<All she did was complain.
? There is a strong difference between attempting to impose order over a class and punishing a class. They are radically different creatures.
<<how do you control the uncontrollable?
With serious courage and massive insanity! Most times the kids bounce between mommy, the cooler, and whatever else the particular issues might be at that second, I propose they were not DOING enough. Or perhaps not enough geared specifically for their AGE!
To keep them from playing "mommy pinball" he might have explained he was teaching them how to be BIG kids... And that the BIG kids he teaches watch him ALL the time. SO they can SEE what he is showing them...
" Eyes on ME please... Jimmy..." "...Jimmy go give your mommy one really, really big hug and then come back until class is done, go ahead..."
You make 100% certain they understand they will be asked to WATCH the class if they are actually disruptive. But the descriptions sound like many, many of the classes I teach.
The class period itself must be geared for the age.
Waving to mommy is benign if once, repeatedly, he needs reminded in a friendly way mommy can't teach him, and needs to "...do what I am doing..." There are word games, behavior mod. 101 but overall it sounds like he was literally overrun.
Asking them in a group to DO specific things you essentially are playing "freeze tag" and coming to see if they are doing it great or super great. In a very young group, you have to make the repetition a game of some kind. A back and forth between your son and them. "...ok, everyone have a seat... who thinks they can show me a great LOW BLOCK..." and you go around the line/circle and pick volunteers out. Praise them.
Line drills become COPY the grown up...
You ask them simple questions and get them to raise their hands with the answer. More than 5 minutes doing rote will crush the age I suspect you are speaking of. It has to be sneaky, and ingenious to get them to do XYZ correctly.
All kinds of games he can "bastardize" to make them martial & appropriate. It is NOT about doing games, but about their learning. "... if everyone does their BEST... we will play XYZ game if we have TIME. If anybody is fooling, we won't play..."
There will be foolers and simply point out "...Johnny, you classmates will not be happy if YOUR fooling means they cannot play..."
All kinds of tricks.
The fact you mention he sent off the "senior kids" with WEAPONS to practice scares me in ways I cannot begin to verbalize. If there are weapons ANYWHERE, it must be 10,000% supervised by you or I (adults) no matter how rubber, how "practice" they might well be. Just too many things that can go wrong even with them. What happens if
Greg hits Kenny whether accidentily or on purpose, could your son disarm them harming neither? Could he make the room freeze on command? Is he aware of kids who are bad partners and likely result in bad things happening...
Teaching is almost never the physical, but how different groups, kids interact. ADD, all manner of different conditions have to be part of the lesson plan and how the lines, activities are formed.
Your description overall badly concerns me on numerous levels I'm afraid...
Merely my opinion, I could surely be mistaken,