Calling Battlefield Earth better than ESB is an abuse of free speech.
Protection of speech is specifically a protection of the exchange of ideas. If your ideas make people angry and they engage in random acts of violence because you said it, you are not responsible for their actions, and you have the right to legal protection against them.
You are not free to say something if you will be legally punished after the fact, or if others will be exempt from prosecution if they opt to punish you outside of the law.
Conflating yelling "bomb" on a plane with expressing ideas leaves the door open to ideas being criminalized. The bomb cryer is not engaging in free speech. They are willfully enciting panic. Speech being the medium of expression doesn't qualify it for protection. It would be like saying I'm free to skin cats so long as it's on a ceremonial altar and I'm a card holding member of the Church of Satan.
This girl's actions fall under neither category. I assume she's just violating school rules.