Question for Jehovah's Witnesses: Who Lied?

The Governing Body uttered the following, as printed in the Watchtower magazine;

"Rather, he has complete confidence in the truth as it is revealed by Jehovah God through his Son, Jesus Christ, and "the faithful and discreet slave."" Watchtower 2001 Aug 1 p.14 

When the truth, as revealed by Jehovah God through his Son, Jesus Christ, and the "faithful and discreet" slave turns out to actually be false, Jehovah's Witnesses have a problem. Either Jehovah lied, and the Bible says he can't. Or Jesus lied, and the Bible calls him "the truth". Or the "faithful and discreet slave" lied.

So, my question for Jehovah's Witnesses is, when the Governing Body no longer believes something they previously taught as truth revealed by Jehovah God, through Jesus, who lied?