Well, yes it is relevant, and she was ASSURED she would not be at risk by ADULTS IN AUTHORITY OVER HER (and responsible for her safety).
The alleged ADULTS had no business asking a minor to participate in an ADULT ACTION, especially one with danger.
The alleged ADULTS did not get permission from her parents, yet the same child would have to have a DOCTOR's and PARENT's written consent to take an aspirin while in school.
If they did not get permission from her parents, they are guilty of violating school policy and STATE and FEDERAL LAW.
I'm not defending the school, just describing the school's legal argument. I think the administrators are lower than low. I haven;t done as much research as you have into violations of state and federal law as they relate to the incident. I tend to disregard school policy, as much of it is nonsense on stilts.
Students should be made wary of promises, suggestions, etc. made to them by teachers and others in positions of authority, and be REALLY wary when hearing an assurance of "promise to look out for you." Those promises are worthless.