In his 1956 work 30 Years a Watchtower Slave, W.Schnell claims that Rutherford knew all along he was telling stories. Schnell maintains that he was once witness to a conversation between Joseph Rutherford and another high-ranking official of the WTS. In this conversation, Rutherford readily admitted that the date of 1925 was pure nonsense, and only introduced for publicity purposes. Furthermore, this beloved president of the Watchtower Society insisted that it really did not matter too much; he reckoned the rank and file could be kept so busy "selling literature" that they would fail to notice they had been conned.
If Schnell is to be believed, the only thing Judge Joseph Boozerford deluded himself about was into believing he could get away with it!
PS: The date 1925 was not plucked entirely out of thin air. As with 1975, there was enough chronological data available in the Bible from which to concoct a story from - a story convincing enough to excite a lot of people. Never underestimate the effectiveness of the half-truth as a propaganda tool!