I notice some here have a real problem with Russell being a Mason. Proof aside, what difference does / would it make if he was or not?
Never say something derogatory about their cult unless you have the paperwork to back it up. If you can't prove an allegation, they will consider that you have fulfilled the WT prophesy about Apostates being liars and you lose you credibility.
Why waste hours trying to defend an unproveable accusation, when that time would be better spent attacking their primary doctrine (... and that doctrine is not the Trinity)
Cheers
Chris