Pedophiles are sick people who generally can't be cured. They do need to be removed from society permanently. It's a deep subject with many complexities, but I stop short of calling an inappropriate relationship with an underage teen as a pedophile. It's more like breaking the law and highly inappropriate (especially by a teacher) than pedophilia, which is a special kind of pathology different from this. Teachers who prey on students need to never teach again and serve jail time for breaking a sacred vow of trust the parents put in charge of their teens. Permanently removed from society though or killed? No. They can be rehabilitated and be productive society members.
Anyway, deep subject and digressing from the topic of this dumb ass coach who scared the shit out this poor girl and will get what he deserves.