It might seem like a mere conspiracy theory to some but current players are concerned about the depth of the corruption. ICC now investigating the media leaks.
But again, if you are not involved, the truth will set you free and you should have nothing to worry about. If they bought drug sniffer dogs through your work, and you are not involved in drugs, then you have zero to worry about.
One thing why I believe McCullum to be speaking the truth is that he is not even the slightest bit worried about repercussions, more that fact that his confidential testimony was leaked. Thus, because he did nothing wrong, he has nothing to be worried about.