My theory is that Moosecat and Siggie are seen as aggressive and competitive - if they get into trouble it is in the context of an overzealous tackle that had to be made at the time. In contrast Griffiths is seen (in my theory) as a player with a careless streak, and more of a "loose cannon" prone to do a stupid unnecessary thing when none was called for just to wind up the opposition. Others may disagree.
There is also the allegation that I've seen bandied around by a few folks across the Tasman that Mr Griffiths is someone who has a bit of a knack of being a disruptive influence in the dressing room. Don't know whether that's true or not. Don't really care.
I'm not particularly happy we've signed him, but I can see and understand why we have. Once he pulls a stripey over his ugly, whining head he'll get my support, albeit grudgingly. Bottom line is that he's a Nix player so, whether we like it or not, WE have to deal with it.