Why didn't you look at Section 116? I'm not an immigration lawyer but it seems more relevant than any of the public interest stuff.
Power to cancel
(1) Subject to
subsections (2) and (3), the Minister may cancel a
visa if he or she is satisfied that:
(a) the decision to grant the
visa was based, wholly or partly, on a particular fact or circumstance that is no longer the case or that no longer exists; or
(aa) the decision to grant the
visa was based, wholly or partly, on the existence of a particular fact or circumstance, and that fact or circumstance did not exist; or
(b) its
holder has not complied with a condition of the
visa; or
(c) another person required to comply with a condition of the
visa has not complied with that condition; or
(d) if its
holder has not
entered Australia or has so
entered but has not been
immigration cleared--it would be liable to be cancelled under Subdivision C (incorrect information given by
holder) if its
holder had so
entered and been
immigration cleared; or
(e) the presence of its
holder in Australia is or may be, or would or might be, a risk to:
(i) the health, safety or good order of the Australian community or a segment of the Australian community; or
(ii) the health or safety of an individual or individuals; or
(f) the
visa should not have been granted because the application for it or its grant was in contravention of this Act or of another law of the Commonwealth; or
.....blah blah blah