D&C 42

As the Lord established His law, He said -

"...I say unto you, that it shall not be given to any one to go forth to preach my gospel, or to build up my church, except he be ordained by some one who has authority, and it is known to the church that he has authority and has been regularly ordained by the heads of the church."  (Doctrine and Covenants  Section 42:11)

It becomes apparent that nothing is to be done in secret in the Church.  That when people are called, it is presented to the Church by those in authority for a sustaining vote -

"For all things must be done in order, and by common consent in the church, by the prayer of faith."  (Doctrine and Covenants Section 28:13)

Thus no one can step forward and claim some aspect of authority or right that was done in secret.  Once a year, in general conference (general officers of the Church), stake conference (general officers of the Church and stake officers), and in ward conferences(general officers of the Church, stake officers, and ward officers) callings and offices are again restated and sustained by members of the Chuch.  Common consent is an acknowledgement by the saints that they are aware and recognize such officers.