So if they paid enough and 9 didn't up their contribution to maintain exclusivity then fox legally can show it
Yes, at present ch9 pays for exclusivity for Origin and Grand Finals. Technically if you look at the list of events every NRL match is on the Anti Siphoning list, I guess they get around it by the games are offered to ch9 but they only purchase 3. Below are the Rugby League events covered under anti siphoning laws.
5 Rugby league football
(1) Each match in the National Rugby League Premiership competition (including the Finals Series).
(2) Each match in the National Rugby League State of Origin Series.
(3) Each international rugby league test match that:
(a) involves the senior Australian representative team; and
(b) is played in Australia or New Zealand.
(4) Each match of the Rugby League World Cup that:
(a) involves the senior Australian representative team; and
(b) is played in Australia, New Zealand or Papua New Guinea.