I cannot say for certain, but I believe Australia still has a statute of limitations on criminal acts, although there was talk about expanding it when it comes to minor victims.  In any case, Pell, a true prince of the church, chosen by the Holy Spirit to teach morality to the laity, is safe in St. Peter's Holy City, far from the reaches of mere secular law, and Papa Francis isn't going to turn one of his brothers over to secular rulers.  Like his sainted predecessor, he knows Cardinals are more valuable than children.  The victims don't matter, the Princes can rely upon the protection of the man chosen by God to be Christ's Vicar.