Oh, we went back. We became members there. I haven't seen this happen again, though. From what I remember (I was 8), it was done very badly.
Isn't the point of what we call discipline, restoration? If we do it with restoration in mind, I'd think the outcome might be much better.
As for witnesses, I think it could be one of two things. Certainly, an eyewitness may be of use (although I wonder how often you'd find an eyewitness to, say, adultery). But this:
or a witness in the sense that an individual believes your observations of the sinful behavior and agrees to support your act of disciplinary restoration
I think is not what a witness should be. Witnesses need to be impartial. Because as we know, if the person bringing the grievance is found (presumably by the witnesses he or she brings) to be bearing false witness, or is just plain wrong or misunderstood about what he or she saw, that person is subject to what he or she would have subjected the original person being accused/faulted/"restored."
Bringing along witnesses who are not impartial seems futile, and smacks of ganging up on a person, rather than trying to come to consensus on how to go forward.
When you say, "is under church discipline," what do you mean by that? Is there some sort of status involved at your church? Or do you mean, if the steps are still going on? On that note, refer back to what I said above about the witnesses. Does it take the first step for someone to be considered "under church discipline?" The second? Because the first and second steps seem to be information gathering, understanding, and consensus building more than anything. No matter what, it doesn't seem to me that much time should pass between bringing witnesses and bringing a matter before the church.
Sometimes it feels like my home church forgets about the restoration part and focuses on the "you're under church discipline," part. I don't want to get caught up in semantics, but I do think we need to examine what kind of spirit with which we go forward when invoking the verses in Matthew. Is it with a spirit of discipline in the sense of punishment and accusation, or is it with a spirit of understanding and restoration?
When we seek to discipline members, should it not be to keep them in, rather than to cast them out?