When an employee is done a mistake intentionally or accidentally, the responsible one for these actions are those employers only. Because, the work assigned by others by trusting the employer only, hence it is the responsibility of the employer to recruit good and faithful employees, if they make any mistake, it is the responsibility of the employer only. Employer is the legally bounded and responsible one if the action happened in the premises of the firm.
In the given situation, the custodian hits the child intentionally and the school is liable for the actions of the custodian.