His regularly scheduled class was cancelled.
That's the funny thing about this. WHY was his regularly scheduled class cancelled? Why it is almost as if the school was encouraging the walkout, as if the school was trying to get as many students involved in it as possible.
Surely you have a different explanation as to WHY his regularly scheduled class was cancelled. Was the teacher sick? Couldn't they get a sub?
It's pretty clear you never went to school, otherwise you would have learned an object can't be in two places at once. The walkout was going to happen with or without the schools endorsement. That meant students were going to be in two different places. Students needed to be supervised and teachers needed to cover both areas. Are you keeping up or do I need to get the crayons out? As to why the school didn't fork out money for a substitute teacher, that money is earmarked for firearms procurement and weapons training. There is nothing left in the budget for substitution.
Incidently, I think you already knew this, you are just being deliberately obtuse. Full marks for your sophistry.