I'm probably quite biased on the topic, having my own history with gambling addiction, but I'm not a fan of people calling for him to be sacked based on something in his past which he seems to have overcome (and good on him for that - its not easy). If his been cleared of any wrong doing, play on.
I wouldn't want my employer firing me for my own personal issues from years ago, especially if it hasn't been shown to affect my work.
The bigger problem imo is the NRL not having a blanket ban on all sports betting for everyone under their employment. Even as a public servant, there are activities I am not allowed participate in, or issues im not even allowed to comment on due to "poential" conflicts of interest. Same should go for sports (and not just for the people playing the game).
I think NFL staff, officials, etc. aren't allowed to bet on any sports... we should be implementing something like that - especially given how much more engrained gambling is over here.