The Magisterium did not make the explicit-implicit distinction and used an irrational premise and inference to project Vatican Council II as a break with Tradition and in particular the dogma extra ecclesiam nulla salus.
Without the irrational inference from the Letter of the Holy Office 1949 , Vatican Council II is Feeneyite and affirms the old ecclesiology.
Lumen Gentium 16 is not relevant or an exception to the Feeneyite version of the dogma on exclusive salvation in the Catholic Church.
The Magisterium had overlooked something simple.People in Heaven cannot be exceptions on earth.Instead they excommunicated Archbishop Lefebvre. They really excommunicated him for not accepting the irrational and heretical interpretation of Vatican Council II, with the hermeneutic of rupture.
The error was clear during the pontificate of Pius XII and the seeds of the confusion were there in the Baltimore Catechism(1808).
Persons in Heaven cannot be exceptions to all needing to formally enter the Church, all needing to be 'card carrying members' of the Catholic Church in 2015 to avoid Hell and go to Heaven.
Archbishop Lefebvre, Cardinal Ratzinger and Pope John Paul II as priests, were unaware of the error.-Lionel Andrades
Brother Francis ( MICM) the former Superior of the Slaves of the Immaculate Heart Monastery in Richmond New Hampshire, USA made a mistake on Vatican Council II ? : excommunication of Archbishop Lefebvre
Script for video The Magisterial Heresy