Unfortunately, as sad as it may sound (some not all) disfellowship people are sincere enough to believe they are unclean in Jehovah's eyes and cannot talk to someone else about their faith because they are a bad example.
In fact, I know of people inside the organization that forbid a disfellowship person from speaking their faith if they do it shows they are not really repentant. There are two groups for and against the question is which group is the elders that reinstated in?
The whole thing is a game people learn to play to be accepted. People will do anything toget back in it has nothing to do with faith or truth or God but acceptance.