I don't get the correlation.. if a player did kill a girl, it would have little to do with any previous incidents (alleged or otherwise) by other players.
It would in the sense the nrl would be blamed for not curtailing a certain culture where violence against women is OK. Why else would they support special interest groups against domestic violence etc. It's all to promote a better image.
You're right in that each case should be judged on its own merits. But that's not the way the media works. They lump all the incidents together and suddenly you have an "epidemic" of violence in rugby league.