Arius becomes an apostate
https://en.wikipedia.org/wiki/Arius
The Bible warns about people like Arius (c. AD 250—336), a Christian priest from Alexandria, Egypt, who was trained at Antioch in the early fourth century. About AD 318, Arius accused Bishop Alexander of Alexandria of subscribing to Sabellianism, a false teaching that asserted that the Father, Son, and Holy Spirit were merely roles or modes assumed by God at various times. Arius was determined to emphasize the oneness of God; however, he went too far in his teaching of God’s nature. Arius denied the Trinity and introduced what appeared on the surface to be an inconsequential difference between the Father and Son.
Can ex-witnesses and the disfellowshiped be considered part of this category if they deny the teachings of Christ by subverting them?