Can my 15 year old son be charged with a class c mis, even if he wasnt arrested or written a citation in TX?

My son was at an after school football game with friends and an plain clothes officer was sitting just a few feet below. Well the officer thought he heard my son use the sh$@ word in personal conversation. My son denied it and it pissed the officer off. next someone in his group did say the F*&^ word and the officer got irrate. My son left and the officer with his spouse got the prin,ast prin and a school cop to investigate. well they found my son later in the restroom and went in and apprehanded him. didnt believe his denial and kicked him out that thursday night. well I made a complaint about his punishment being 5 days ISS 4 days later on monday. well the school admitted that they called the plain clothes officer back and requested he come up and write a statement. well he then decided to press DOC/language charges. We received a letter in the mail from a jp court ordering our appearance. The office wrote an afidavit at the school police department and my son or I was arrested,cited or anything, just notifyed by the jp court of the complaint and ordered to appear. I believe it was retaliation as my complaint was over a 504 issue and that is suppose to be protected by law. We pled no contest in jp court and are appealing it in county court. However isnt their laws about arrest,maranda rights and such.