Mankkeli quoted from WT (assumption) the following
14 Consider what Jehovah’s anointed servants, the figurative “two witnesses,” experienced in 1918 and 1919, when their enemies ‘framed trouble by decree.’ (Revelation 11:3, 7-10; Psalm 94:20) J. F. Rutherford (then president of the Watch Tower Society) and seven associates were unjustly imprisoned. At that time, the “two witnesses” were killed as far as their prophesying was concerned, and their foes rejoiced.
It would be helpful if you stated where you were quoting from and the year it was published.
This article states that the two witnesses were killed because of their prophesying and that was in fulfillment of the scriptures. Yet the org says they do not prophesy and anyone who makes prohecies and they do not come true are false and their words are not from God.