Each of the following is a ground for amending, suspending or cancelling a person’s authority as a crossing supervisor—
(a) the person has, since becoming a crossing supervisor, been charged with, or convicted of, a disqualifying offence;
(b) the chief executive considers—(i) public safety, particularly the safety of children, has been endangered, or is likely to be endangered, because of the authority; or(ii) it is otherwise necessary in the public interest;
(c) the authority was issued by error or was granted because of a false or fraudulent document, statement or representation;
(d) the person has contravened a condition of the authority;
(e) the person can no longer perform the role of a crossing supervisor satisfactorily, including because of any known medical condition or physical or mental incapacity.