(a)
the conduct alleged to constitute the offence was done for a genuine medical
or scientific purpose, or
(b) the conduct alleged to constitute the offence
was done by a law enforcement officer for a genuine law enforcement purpose,
or
(c) the conduct alleged to constitute the offence was required by a court
or otherwise reasonably necessary to be done for the purpose of legal
proceedings, or
(d) a reasonable person would consider the conduct of the
accusedperson acceptable, having regard to each of the following (to the
extent relevant)--
"law enforcement officer" means a police officer or other person who exercises
law enforcement functions under a law of this State, another State, a
Territory or the Commonwealth.