You are now implying that he didn't have the power to bring justice to the victims, but when you heard that about the parents in some cases being unable to do anything about what was happening, you blamed the parents.
You have different standards for different people.
Cardinal Law only had the power to remove these priests from their faculties in the Diocese, he could not hand them over to the police. That would have required the permission of the children's parents, who were, in many of the cases, reluctant to force their children into the public eye. Or as someone mentioned, it was possible that they were intimidated into not bringing charges.
To the extent that anything Cardinal Law might have delayed that outcome, he would be responsible, but the AG didn't find anything that the Cardinal did that was illegal, even though the AG stated in the press conference that he wished he had found something on Law. The fact that Law tried to help Geoghan seems reprehensible to people who wanted to see him pay for his crime, but Law felt that it was his duty in his capacity as Geoghan's 'Pastor' to minister to him even while acknowledging that he had sinned and committed these horrendous crimes against children and young people.