There is no money laundering without a predicate offence resulting in income generation. In discussed case the committed "crime" is a crime of the same kind as "crimes" of "apostasy", "sodomy" or "anti-Soviet/anti-Government agitation". That's not legitimate criminal charges.
And since the religious group was deprived its legal personality, it cannot be a taxpayer, and accounting isn't required. It can be considered like some persons collectively used their personal income - on which income tax was already paid - to fund their group activities. Therefore, there was no tax evasion.
"An investigation WOULD reveal money being funnelled back to USA; where else would Watchtower want it to go but to themselves?" - According to the police press release, donations were collected "for paying the expenses of rental of premises for conducting meetings with members of the organization and purchasing and maintaining computer equipment" - and also for "transferring them to leaders of the religious organization 'Administrative Center of Jehovah's Witnesses in Russia'" - a claim that's very vague and can be understood in multiple ways.
Finally, I'm for full transparency of religious finances but that's irrelevant here.