To my knowledge the GB has never claimed to be infallible. However the insist that their "New Light" must be adhered to as if it were. Disloyalty to the GB (be it questioning oficial policy or doctrine) is considered by them to be disloyalty towards God. Yet in the Bible there were many cases of those who questioned the established authority and were considered loyal to God.
Christ said that his "yoke was kindly and his load was light". Does the actions of the GB mirror this statement or does it seem to be in opposition?
Are they like the Pharisees of Jesus' time who won't even lift a finger to help others with their load?
Personally I do not believe that the GB speaks for God, nor have they ever. Jesus said that no one could come to the Father except through himself, yet we are supposed to believe that God would use a group of men who constantly contradict themselves.
There is no place in the scriptures where God ever changed His teachings. Nor did his Son. Jesus may have added to what was already established, but he never abolished the old teachings. Yet repeatedly this has been so with the GB.
Clearly the GB serves themselves and are afraid of losing their authority (much like the Pharisees who sought Jesus' death) and so they enforce harsher and more strict rules. There seems to be little choice for them in this matter for where would such aged men go? They have only their holdings in Brooklyn and New York and without them would be on the street (much like the ones they cast out in the 80's). So rather than owning up to their lies and taking the chance that they would lose their power. They instead tighten their grip all the more. But history has shown what happens to such ones. It may take a while but every despotic regime falls. Even the GB will fall and along with it the entire WTBTS organization.