I think it’s likely the suicides are unrelated to the hypnosis, almost certainly the car wreck. Maybe it was related in the sense that he was trying to help some troubled suicidal kids, when no one else would. Odd story.
It’s like the adult who is off spending time alone with some kid they’re supposed to be in charge of. Maybe they were reading bible verses and solving world hunger but it sure looks bad. Put another way - principal has a lot of ‘splaining to do.