It is unbelievable. The teacher objected to the flag despite the fact there is :
1- American Flag in front of school on pole.
2- American Flag painting in school office.
3- American Flags in some classrooms.
I suspect this particular teacher is incensed at all these displays, but chose the school concert venue because it was open advocacy of the Flag by students.
Libs hate that ...
4- The school is based in America.