Gross and habitual neglect of duty as ground for dismissal practice question

Ms. Liza Ramos was a Grade 4 adviser at St. Anne's Academy. During a school-sanctioned year-end pool party, she allowed a student, whose parental consent form was unsigned, to join because the child's mother brought her to the school with lunch and a swimsuit. Ms. Ramos was the only adult present. While she briefly left the pool area to look for two students who had wandered off, another student drowned. The school dismissed Ms. Ramos for gross negligence resulting in loss of trust and confidence. Ms. Ramos filed a complaint for illegal dismissal, arguing that her negligence, if any, was not habitual and thus not a valid ground for dismissal. Should Ms. Ramos's dismissal be upheld? Explain.