The bishops are subject to the pope who is their master in authority in the traditional Catholic teaching. Unfortunately, VII 'Council' amplified the doctrine of primacy from the First Vatican Council by giving greater weight to the Episcopal ministry. Thereby all somehow rule the Church together with the Roman Pontiff. I.e. in Lumen Gentium bishops rule with the pope many times. This is deviation from truth by which papacy has been enriched by men amplifying, expanding and enriching divine constitution established by Christ and doctrinally confirmed, i.e. in Pastor Aeternus.
Cardinal's statement is in contradiction to Pope Benedict's document and reality. However, it is logical, philosophically consequent and in line with their election of Francis and
renewal of absolute dedication and unconditional love for his august person Francis, in whom they recognize the Successor of Peter and the Vicar of Jesus. Munus and ministerium should occur mutually in practice, in as much as, the Episcopal order is in communion with Peter, as Christ commanded, to be subject to and obey Peter. "Otherwise it necessarily becomes a lawless and disorderly crowd." (cf Satis Cognitum 15)
In consequence, exercising power of teaching and ruling (ministerio) by a Roman Pontiff is dependent upon the bishops' communion with Peter's successor. It is clear that it was not so in the case of Pope Benedict XVI after numerous documented external and internal attacks. Whilst mafia of Cardinals from Saint Gallen plotting to overthrow BXVI has officially revealed itself the remaining Princes have decided to remain silent after having elected a second 'pope'. One, whether a canonist or a simple man, will not understand what happened unless the papal crisis is analysed integrally instead of its particular elements taken out of context.
Pope Benedict XVI received munus (Petrine Office) what is conferred forever. Unfortunately, he was practically unable to exercise power (ministerio) for aforementioned reason and therefore only abdicated from teaching and ruling but not visibility of Pope. In his
first homily he has clearly foreseen this fact of wolves in sheep skin making him flee. [
"Pray for me, that I may not flee for fear of the wolves."] Practically flee from ministry to the quasi-shared Petrine Office stemming from Conciliar collegiality against Scripture, Magisterium and decree of Roman Rota making it not valid and still true POPE, as there can not be more than one pope.