"When I bring up to still in friends about the worst case of abuse in the UK, Eunice Spry, who abused 4 children for 19 years, they say she was not a Jehovah,s Witness (like she was just pretending)..."
When they say that you can reply by saying that all the so-called Catholic priests found guilty of molesting children were not really Catholics but were just pretending; and the members of the Catholic hierarchy who participated in covering it up are also not real Catholics. All the sins of the Catholic church were committed by "false brothers" who weren't real Catholics.
When they use stupid, special pleading reasoning to excuse their sins and wickedness, use the same reasoning right back at them to excuse the sins and wickedness of "christendom" and "babylon the great" so they can see how stupid and hypocritical they are being.