If that is the case then wouldn't the Biblical teachings about God chastising His own, and in worse circumstances God disciplining His own, and more severe then Church discipline, and then in the most severe cases even having His own excommunicated & turned over to Satan for a time be applicable?
All of salvation is monergistic, and certainly this includes the preservation & perseverance of the saints.
Though what evidence of true saving faith existed in the previous circumstances?
And how bad is the state of being "back-slidden" from a pure state if true?

Whatever the case (and only God knows for certain) ==> the current state of their souls is terrifying and dreadful.
Just thinking about these things should cause us all to tremble!!! But then giving words to them in this thread should drive us to our knees, and even to our faces flat on the ground begging God to guide and keep us, and to save them.