(1) If a past act is an act attributable to the Commonwealth, the act is valid, and is taken always to have been valid.
(2) To avoid any doubt, if a past act validated by subsection (1) is the making, amendment or repeal of legislation, subsection (1) does not validate:
(a) the grant or issue of any lease, licence, permit or authority; or
(b) the creation of any interest in relation to land or waters;
under any legislation concerned, unless the grant, issue or creation is itself
a past act attributable to the Commonwealth.