The Hands being instructed in the Will to be ever watchful that there be no opposition to the guardian, and to cast out anyone who does so, that is pretty closely defined. And that must be within their limited jurisdiction. You have to remember that the existence of a Hand is predicated upon there being a guardian. And Shoghi Effendi relegated that function to himself. It all gets back to the matter that there must be a guardian in order for there to be a Bahá'í Faith. We also learned from `Abdu'l-Bahá that there has to be a guardian in order for the Universal House of Justice to have a God-defined president. As president of that body, he carries the Germ of God to their deliberations. He is the only individual who carries that to their deliberations. The Will does not prescribe any sort of infallibility upon the UHJ without the presence of the guardian, a guardian who is appointed by God. That guardian is the one who carries the Germ of God to its deliberations. When he does so, the UHJ has its level of infallibility. However, the guardian is the only one prescribed with the level of Infallibility to interpret Holy Writ. It all gets back to the presence of a living guardian, a living guardian who carries the Germ of God, which may be used within certain prescribed conditions, and only those prescribed conditions. Without a living guardian within their midst, the UHJ is not a complete entity, and lacks any of the authority intended by `Abdu'l-Bahá.
Lets look at the concluding words of the Will and Testament: "To none is given the right to put forth his own opinion or express his particular conviction. All must seek guidance and turn unto the Center of the Cause and the House of Justice. And he that turneth unto whatsoever else is indeed in grievous error. The Glory of Glories rest upon you."
