The NRL keep claiming for years and years now that they have had investigations and talks with technology partners and there are several solutions on the market already put to them, but they fail to take the step to implement them. Probably because its a good way to "overlook" decisions and then say "oh we can't review that with video ref".
Effectively you can throw the ball forwards as long as the touchies "accidentelly" dont happen to notice it, nor does the ref.
So pretty much before a game officials can be coached to ignore forward passes or "not see them" from one side, and nothing at all can be done about it.