This was for Weakland to address.
Another aspect not mentioned is that Cardianl Ratzinger during that time period was in the Congregation of the Faith. The responsibility for priests (unless it involved false teaching) is the duty of the Congregation of the Priest.
It was not until Weakland claimed that the priest in question had broken the secrecy of the confessional, which would fall into the Congregation of the Faith.
It is too bad that Bishops can not be defrocked. Weakland is deserving of it, during this whole affair, he was having his own homosexual affair, stealing thousand of dollars in church funds to pay off his lover.
Bishops can be removed, but it's a very serious thing and never done for something trivial.
Weakland's homosexual affair and his payoff (he paid the money back, BTW) came out after his retirement. If it had come out much earlier, he probably would have been removed or forced to resign, IMO.
He was an awful bishop, and the general reaction among FR Catholics when he retired was, Deo gratias ("Thanks be to God!").