Gamesmanship and shithousery conveniently become "Hey, it's legal! Okay, maybe not a good look, but it's up to the IRL/FIFA/Whichever Governing Body to fix that loophole if they think it's a bad look for th game!" when your team does it - Park The Bus Football, gang-tackling in league etc etc.
What Curran did has been going on since sports began, it's just that he's a Pioneer in the ref pinging him for Taking The Piss And Acting Like You're Me. I look forward to seeing NRL players telling their opponents they're offside/whatever infringement being called a penalty since a precedent has been set...NOT.
Or did the ref simply look at Josh and still see the Warriors jersey he used to wear?