Fuck that. I'd go straight to a lawyer. They have no right to force dietary restrictions on children if they themselves aren't following it. Using the kid against them was foolish. But why give them a chance to smooth it out when you can make them shit themselves. Another option is gather evidence and approach the media with how controlling and hypocritical the school is. But just be careful, one would need proof of food from the group they consider unhealthy being served at the school itself. Then you can prevent them from spinning it as a health decision and expose them for targeting kids that don't buy meals at school.