The incident itself was a regrettable blight on the game, but there’s context worth keeping in mind: firstly, that it’s difficult to tell a mate/teammate not to do something, even if you disagree with it. It puts you in an awkward and difficult position. Secondly, he may not have explicitly known what it was that they were doing, but he chose not to dig further for fear of what he’d discover. These two points constitute a failure of leadership for sure, but I think it’s a little cruel to flatly label him a cheater.
Maybe I’m being overly biased as an Aussie, but even if we discount my version above, I still think it’s wrong to label a man a cheat for one isolated incident. He is otherwise of good character. Happy for you go to nuts on Warner, however...