Luke 12:2
Luke 12:22There is nothing concealed that will not be disclosed, and nothing hidden that will not be made known.
receives little JW commentary in apologetic publications. Where it appears, it is treated as a general principle that hidden things will eventually come to light at God's judgement, with no specific application to organisational practice. The "Shepherd the Flock of God" elders' manual — which contains the rules governing judicial committees and shunning, and which rank-and-file Witnesses are forbidden to read — is treated as routine internal procedure, not as the kind of secret thing Jesus warns against.
Hold alongside (Jesus: "I have spoken nothing in secret") and (Paul: "we have renounced the shameful underhanded things"). Then ask the Witness whether the Governing Body operates by Jesus's standard. Witnesses can be disfellowshipped and shunned according to procedures laid out in a manual they are forbidden to read. They can be judged by rules they have never seen. The 1997 Watchtower itself said "true religion in no way practises secretiveness." The verse exposes the contradiction: Jesus warned that hidden things would be revealed precisely because hiddenness is incompatible with the way God's truth operates. A church that judges its members by secret rules is not following the pattern of Christ's open ministry.