Kairos: I'm convinced that witnesses do not understand the definition of evidence.
Sure they do.
It's when someone on the GB introduces a new doctrine with the word: evidently.
"He [Jesus] evidently meant that the lives of the anointed who were on hand when the sign began to become evident in 1914 would overlap with the lives of other anointed ones who would see the start of the great tribulation." Watchtower 2010 April 15 p.10
"John Barr ... twice read the comment: "Jesus evidently meant that the lives of the anointed ones who were on hand when the sign began to be evident in 1914 would overlap with the lives of the other anointed ones who would see the start of the great tribulation." We do not know the exact length of "this generation," but it includes these two groups whose lives overlap. Even though the anointed vary in age, those in the two groups constituting the generation are contemporaries during the part of the last days. How comforting it is to know that the younger anointed contemporaries of those older anointed ones who discerned the sign when it became evident beginning in 1914 will not die off before the great tribulation starts!" Watchtower 2010 June 15 p.5