Of course, a close allie of this 'the organization is imperfect' defense is the thought 'we never said we were God's prophets' which is normally brought out to counter the scripture in Deuteronomy 18.
Not true - the society have repeatedly claimed to be God's prophets:
The following quote is taken from the book ‘The Nations Shall Know That I Am Jehovah,’ 1971, pp. 58,59,61,66,67.
<<Who, then, are the group of persons who, toward the beginning of this "time of the end," were commissioned to serve as the mouthpiece and active agent of Jehovah?.... Whom could the real "chariot" of Jehovah's organization roll up to and confront that He might bestow upon this qualified one the commission to speak as a prophet in the name of Jehovah?.... Jehovah has found and commissioned his modern-day "Ezekiel." It is a composite Ezekiel. It is composed of those dedicated, baptized proclaimers of God's kingdom, who have been anointed with His spirit for their work.... Jehovah commissioned this dedicated, baptized, anointed class of servants to speak to all the nations in His name.... So it was with the anointed, dedicated witnesses of Jehovah back there in the year 1919 C.E. The facts from then on down to this date prove that they received their ordination and appointment and commission for their work in this "time of the end" from Jehovah himself.>>
Ask yourself, if you are a JW, can you say to an elder that you can take or leave what the WBTS say to you because they are, after all, imperfect men and therefore an imperfect organisation? NO! They will not let you - they will tell you that the GB are God's visible organisation on earth and to ignore them is to ignore GOD HIMSELF! The 'the organization is imperfect' defense only comes into play when embarrased members try to gloss over past mistakes. Under normal conditions the WBTS DEMANDS that they be treated as God's infallible organisation.