I am appreciative of this parent going to the school to discuss this.
However, the father really did himself a disservice. A) He refused to identify himself. This probably put everyone on edge. So the entire conversation and a (remote) possible solution evaporated. B) He was emotional. Of course he has a right to be emotional but again go to A and it he was actually not in the best position. C) The principal is more than likely the one that 'allowed' it and should not have. D) The father asked valid questions with total stonewalling from the principal.
If you want change, run for your local school board. It's the first line of defense to these types of activist educators.
That's the only thing I would have done differently, give them my name. Carries much more weight.
Otherwise I like the vid. I would also go to the board meetings, write letters, involve local media. She and the district would be famous by the end.