Maybe we should direct JW's to read this Question Box revelation:
w06 2/15 p. 31 - "Finally, Jesus explained that if a person addresses another, “You despicable fool!” he would be liable to the fiery Gehenna. What, then, did the expression “despicable fool” signify? It designates a person as morally worthless, an apostate and a rebel against God. So the person addressing his fellow as a “despicable fool” is as much as saying that his brother should receive a punishment fit for a rebel against God, everlasting destruction. From God’s standpoint, the one uttering such a condemnation against another could merit that severe sentence—everlasting destruction—himself."
If a JW falsely slanders someone of being an apostate, they're condemning themselves.
Apostasy and heresy are not the same - the cult should educate themselves.