Has Australia joined the Axis of Impunity?

Today's Sydney Morning Herald has an article about the one-sided extradition arrangement between the US and the UK, which are likely to see three British citizens tried in Texas under Texan law for a financial fraud committed in the UK. But the interesting bit is what is said in passing at the bottom:

(Australia itself, in a little-publicised concession several years ago, agreed to indemnify all US citizens against extradition to face charges before the International Criminal Court, even though Australian Foreign Affairs Minister Alexander Downer has been a big fan of the court's establishment all along and has fought hard for it.)

Has Australia joined the Axis of Impunity? There's a story from The Australian from 2002 which suggests that the Australian government had at least agreed in principle to American impunity - but I can't find anything else. I'd love to hear if anyone has anything solid on this, so I can update my map.