Apparently, the talk was entitled "Choosing the Best Way of Life", and was given at the 1979 "Living Hope" District Convention. This talk, I presume, was the one that released the book by the same name.
Another quote: w80 3/15 p.17 par 4.
In its issue of July 15, 1976, The Watchtower, commenting on the inadvisability of setting our sights on a certain date, stated: “If anyone has been disappointed through not following this line of thought, he should now concentrate on adjusting his viewpoint, seeing that it was not the word of God that failed or deceived him and brought disappointment, but that his own understanding was based on wrong premises.” In saying “anyone,” The Watchtower included all disappointed ones of Jehovah’s Witnesses, hence including persons having to do with the publication of the information that contributed to the buildup of hopes centered on that date.
(italics theirs)