It seems we have a contradicition here:
"Determining whether someone has gone far enough to be guilty of gross uncleanness or loose conduct is a serious responsibility, for lives are involved. Those judging such cases should do so prayerfully, asking God for his holy spirit, discernment, and understanding. Elders need to maintain the purity of the congregation and must base their judgment on God's Word as well as on the direction of "the faithful and discreet slave."
Watchtower Magazine 7/15/2006
"Jehovah can read hearts, while we cannot. This in itself is a good reason for us not to be judgmental. We do not know all of another person's motives. We should try to imitate Jehovah by not fixing our attention on human imperfections, which will eventually disappear."
3/15/08 Watchtower Magazine