Comments made by prophets or General Authorities cannot be used as evidence against the church because they are not considered official revelation unless uttered by the prophet, sustained unanimously by the 12 and also by the church as a whole.

The church has established the precedent for canonizing new revelation and saving ordinances by including them its Latter Day scriptures. The scriptures have officially been accepted as revelation.
The ordinances of baptism, confirmation and the sacrament are included in the canonized scriptures and so are by definition revelation.

The church considers temple ordinances so necessary that without them one cannot go to the Celestial Kingdom.
As far as I am aware, the ordinances of the temple, washing and anointing, baptism for the dead, ordaining to the priesthood, the endowment and sealing, have not gone through any approved process of canonization which would certify them as revelation. It thus follows that these ordinances can not then be considered official revelation; they cannot be considered inspired, infallible or binding.
At present, these highest ordinances of the gospel could contain many errors. If someone is to make such solemn covenants as the temple requires, in order to secure the highest possible blessings God has to offer to his children, it follows these ordinances should be held to the highest possible standard. The members should be absolutely certain they are official revelation. These ordinances must go through the church mandated process:
1. Presented to the body of the church by the prophet in a session of General Conference
2. Sustained unanimously by the Quorum of the Twelve
3. Sustained by the general membership of the church
4. Included (the full and complete text of all these ordinances) as additions to the Doctrine and Covenants.

In the absence of these actions I say it is pointless to perform these ordinances for either the living or dead.

That's just one part of a contradictory tradition. The other part is that any prophet or apostate can make it up on the spot, and that it may be true before any meeting or discussion occurs. Maybe it stays secret or ambiguous forever, but you can be condemned for not recognizing its inherent truth.

Not a good system.

The only real rule is that the modern prophets are in charge.