Fisherman: In this hypothetical case, the testimony of 2 witnesses was necessary to establish the truthfulness of the accusations of idolatry.
Exactly. That is how serious 'God' viewed those who dissented from the ways of the culture being established at the time. Anyone who didn't follow the same ways were to be put to death. Loyalty was prized and disloyalty was punished with the most serious punishment of all - death.
And then the scripture goes on to speak of other judicial matters - the matters that are common to all societies. Ones that don't require death penalty (disfellowshipping).
Disfellowshipping/death was the punishment for not believing in the same god. Death isn't mentioned for the other sins/crimes.
And that reveals how cruel the WT actually is. They disfellowship for any and all perceived minor sins/crimes. They stone the sinner. They have perverted the original meaning of the law.
And, they are using that law to take secular law decisions into their own hands. That isn't cool. They have no authority to do so.