Bowing Your Head = Establishing a National Religion?

According to a press release from the Rutherford Institute, a football coach was prohibited by his school system from "from bowing his head or 'taking a knee' during pre-game student prayers."

There are two religion-related clauses in the Constitution (First Amendment):

- Congress shall make no law respecting an establishment of religion; (the "establishment clause")

- or prohibiting the free exercise thereof ("free exercise" clause)

That's it. That's all it says, and it says that in the context of limiting the power of the Federal Government from making laws. How does a school district (aided by Americans United for Separation of Church and State) get so far off the intent of this amendment?

When students choose to initiate a prayer, is the coach supposed to stare straight ahead? Which of the 2 religion clauses is the most in danger of violation by a coach bowing his/her head? Does that establish a national (or state) religion? Or does saying a coach can not make any gesture of recognition violate the free exercise clause? I think the latter applies.

Also note that the First Amendment does not talk about the government's actions regarding establishment of religion. It specifically says "shall make no law" - that seems very clear, especially considering the extremely high literacy of the people who wrote and ratified the Constitution. So it is a long, long reach to say that if I bow my head during a student prayer, that I am establishing (with the power of law) a state or federal religion.