After ten years, I think I've figured out the Howard Government's winning formula for running a scandal. Once the story breaks a new line is adopted each week until the issue peters out: "We didn't know", "We weren't told", "We didn't ask" and "We didn't have to ask". If it's still running after a month, use "The public has moved on".
Sadly, this pattern will continue to work until the electorate understands that "we didn't know" means "we can't run the Government". Ministerial responsibility demands that ministers should not be able to shield themselves with ignorance.