I don't see how it's binding if the governing body hasn't registered it.
Its a funny bit of legal wrangling.
The NRL don't contract players individual clubs do, when a player signs a contract they sign it with for instance the Bulldogs Pty Ltd. Its an individual business to the NRL so they have the rights of a normal business to enforce a signed contract.
However if the NRL do not sanction the contract the player can not play in the NRL.
Parra in the end decided not to enforce their contract and released Josh from his obligations but the NRL had no authority to make them do that.
I can't see the bulldogs letting Liccha back out without a fight given it looks like they have been after him for a while.