Some fallen preachers do not go away, so you have two problems: how do you deal with them on the outside, and how do you deal with them spiritually? For the first question, we've already seen that "Restoration," the doctrine that having repented, the fallen preacher does not have to obey God's commands, is false.
Now we add Romans 2"1 "Thou that judgest doest the same things." If they fallen preacher is attacking his critics (some of whom are his victims), he is describing himself. The pastor's son is accusing his critics of being hypocrites. Whether or not that's true, he is describing himself. Shortly afterwards, he began marketing a crooked work-at-home scheme.
When you see this kind of behavior in a fallen preacher, you need to keep your distance.