No, I definitely don't think they're clean. But fixing the Brownlow could literally bring down the organization. There is simply no way they would risk it just to avoid an awkward situation.
FIFA is still going strong after taking bribes for where to host the biggest sporting event in the world.
100m sprint is still a big thing even though 90% of the WRH are found to be doping.
You'd think these things would bring them down but in reality, people just don't care enough or don't have the power to do anything.