This is one instance where a lawyer rabidly threatening the principal, the school board, the school district, the nurse, the community property of their spouses and their pet dogs with a multi-million dollar lawsuit for mental cruelty, false arrest, child endangerement, long term psychological harm and Latin phrases they have never heard before would actually serve a useful civic purpose.
It certainly sounds like the girl has a grievance under the Americans with Disabilities Act. Wheelchair ramps - check. Handicapped parking spaces - check. Wide bathroom stalls with railings - check. Common asthma medication - uhhh...
I'm sure that the school had been advised that the girl had asthma and had been given a list of her medications. Part of the nurse's friggin' job is to be aware of all such disclosed conditions and to stock the First Aid cabinet appropriately.
The principal and school nurse should both be kissing that boy's feet, not booting him to the curb.
Lawyers are like a pack of slavering attack dogs. I wouldn't want to associate with them regularly, but when you need them there's no substitute for a really big, mean, nasty one...