I think you are mixing up two separate things, mercy for child abusing clergy and no mercy for divorced.  The bishops do not get married, that is a problem for the laity and the bishops are appointed to lead, teach, and judge the laity.  Abusing children, on the other hand, as we know from Benedict 16's own family, is something that some, if not all, of the bishops indulged in, from time to time.  Since it concerns clergy, like themselves, mercy is justified.  Is this they are walking in the footsteps of Saint Pope John Paul II, who worked tirelessly to protect child abusing clergy, and as he was a direct infallible successor of Pope Peter, the german bishops are walking in the footsteps of Peter himself.  Remember, the key here, the abused, like the divorced, are laity, and thus sheep subject to the shepherds.