1.) Two elders can witness a brothers car parked outside a sisters home over night and not need two witnesses to say they committed fornication. THAT's why the two witness rule doesn't make sense.
2.) Also Angus Stewart mentioned in case 29 that in Deut 22:25-27 if a woman is raped in the field, she didn't need two witnesses to have the raper stoned to death. Another reason why the two witness rule doesn't make sense.
3.) But let us not forget this important thing. Sure, the org needs two witnesses, but that's to perform their own internal judicial trial process. They should still inform the authorities even if they can't move forward internally. IF the authorities find the perp guilty THEN they can move forward internally. How hard is that?!