Everybody is at Risk

"For although a man may have many revelations, and have power to do many mighty works, yet if he boasts in his own strength, and sets at naught the counsels of God, and follows after the dictates of his own will and carnal desires, he must fall and incur the vengeance of a just God upon him." (italics and bold added)

Doctrine & Covenants 3:4

This applies even to powerful seminary teachers. When someone testifies of true principles, the Spirit bears witness of those principles. The Spirit teaches us of true doctrine, not of other people's worthiness. Unrighteous people can bear strong testimony of true principles, and the Spirit can testify of the truth of those principles. Great men can fall, the church is still true.