You guys don't get it. Johns leaving over this incident would be absolutely catastrophic for the NRL. It would not only have the complete opposite effect they would desire in terms of making an example of him in respect to his behaviour, it will give the media ammunition to attack their judiciary, their rule book, and general policies for years to come.
If Johns does leave, his claim of being scapegoated will be examined by every newspaper around. They will compare punishments for high hits, swearing, anything to make the point that the NRL does not treat its players equally. They will latch on to single examples and use them to shoot the NRL full of holes. The media is like that - it is by nature sensationalist, and that sort of story would generate more attention. They will stop writing of him as a spoiled brat and make him into a martyr instead. 'Good riddance' only lasts a day - 'the best player ever was hard done by' can go on for weeks. Take my word for it, it is the latter story that the media will run.
Johns is not, at the moment, bigger than the game. If he leaves now, in these circumstances, he will be.
I think he knows this. I would be very surprised if the comments he has made aren't simply a ploy in order to ensure that the judiciary is leniant.