Hi scootergirl,
In answer to your question the W.T. Society didn't know what to say after Fred Franz's blunder. He pushed the date the hardest disregarding the warnings of more cautious Watchtower big-wigs. Fred could get away with it because he was their best & really only resident "prophet" and was "co-annointed" by the Judge(Rutherford) himself along with Knorr to rule the Watchtower Kingdom after the Judge's death.. These guys were the top commanders in those days so no one could veto them. Knorr went along with Fred because the growth rate was so huge starting with Fred's ravings in the mid 1960's promising only "a few short years left" until the "end of the 6000 years" of whackey W.T. timetables. This, after years of post WWII stagnation in growth and unfullfilled promises, was like a breath of fresh air for the average Dub. It also helped that the 1960's were so turbulant and filled with changes that it looked to many (even the "worldly" experts at the time) that all Hell was breaking loose anyway. "How could this Old System even last another 10 years at this rate?", was a common JW expression in those days.
Fred clearly promised in numerous writings and speaches that the mid 1970's would mark the end of 6000 years since Ol' Jehover rested from his creations. Though not exact, he promised Eve was created within "only a matter of months" of Adam so we could be assured that the mid-1970's would bring huge changes as it marked the start of the last thousand years of God's seven thousand year "day" left for the millinial reign of Christ in the "New Order". In common Dub understanding this meant the big "A" was due some where around 1975 and Fred knew exactly what to say so we could decode it out that way. Any JW who says this wasn't so is either self-deluded, a liar, or doesn't know what they are talking about.
Also, don't forget how well this date (1975) fits into the whole 1914 Generation notion. People old enough to "understand" the importance of Christ's Second Coming were said to be at least in their mid-teens by 1914 and would be around 75 years or older by 1975, a mature biblical generation by Fred's calculations and the big "A" had to happen before they started dying off. Yeah...Right!
As had happened on numerous occasions with crazy Watchtower "spirit guided" predictions, Fred & the JW's were wrong, AGAIN!. The mid 1970's dissolved into a real non-event time. All the Doom & Gloom predictions by the 1960's wordly "experts" also sputtered into over-alarmist non-history. We survived and the world went on just as usual with crisis after crisis solving itself. Those hippie kids didn't kill everybody while high on drugs, race riots didn't turn into a civil war, no nukes fell, and Rock music and dirty movies didn't undermine the foundations of Western Civilization.
We rank & file Dubs were just stunned because nothing was really happening. And the Society was suddenly very quiet about nothing happening. We waited hopefully a little longer into''76, then''77. We got Star Wars, Mork & Mindy, and Disco but other than that no big "A" in sight. The Society started backing off the big "A" talk. Soon it was the unnamed "Over Zealous Brothers's" fault that so many were disappointed. Then it was the Rank & File JW's fault for being "time watchers" and "fair weather Christians". Then yet again unnamed Elders in distant congregations pushing dates for their own selfish needs had caused the 1975 thing. Let's get real folks, the Society would not tolerate any JWs or especially elders pushing a date unless Fred Franz & Knorr encouraged it. These mysterious Date Pushers would have been DF'ed if they were really making up the 1975 thing. Yet, this JW explaination myth still survives, especially for Dubs too young to know any better.
How could it be the Watch Tower Society's fault since they are "Spirit Directed"? They hoped that the average JW would be too stupid to remember where they got their ideas about 1975 and by and large they were right. Ask an active JW today about 1975 and they will swear that the W.T. Society never made such an error. Most of them won't even know who Fred Franz was even when nearly everything they believe was made up by this one man.