Bibically there is no scriptural grounds for restrictions place on a person after they have repented! Actually having such a long disfellowshipment should be punishment enough! according to Pauls Teary letter see 2 Corth,.
One needs to know what their restrictions are such as not answering at book study, or going out in service. During my restriction, I was clueless because in the 70s they did not have anything like it and the elder neglected to tell me I could not answer at meetings!
As one elder explained, restrictions is just another step they use to see if a person is serious enough to stay with the congregations. The elders stated that some people come back with worldly thoughts such as partaking! One elder said most people come back and think they should partake, and they do not last. Although at the time, I explained to the elders that I did not care about partaking. One elder said yes I know but some people do! Once again, I had to do research as to why! to see why would most care.
Anyhow, the elders will appoint a pioneer to have weekly bible study and to bring you up to date what is new to the organization. If anyone is going through this it is better to keep it strickly bible study only answer the questions from the book and move on. During my weekly bible study, my pioneer became big headed, almost like she thought she had power over me, and she made it clear that she was at my house only because the elders told her to do so. She also packed up her grandchildren gifts and took vacation time at Christmas! She was also teaching things that Jehovah Witnesses did not believe. So I told the elder I no longer wanted to study with her and why. They took her side and said she would never say that!
Also it is not a good time to share your new found research although the bible says if one has some doubts to ask. For example, I express to the elder on the phone that I did not think that Jesus was an archangel. After that conversation, the pioneer came to my house with another woman, and at the end of the study they talked about Michael the Arch Angel. I felt like they were trying to trap me in saying that I believe Jesus to be Jehovah! which I did not believe. Later, I found the same quote in a 1960s WT.
Also, the elder broke his promise to me, I guess he was relieving his own guilt claiming to want to help me out! He stated the reason why I was dfd and that was between me and my original elders. He was not an orginal elder and promised that he never need to know. That was it for me!
Trust me, tell your friend to say little as possible to the elders and when going thru the restriction remember that person who is study with him is not his friend but to report back to the elders! I was shocked when the pioneer expressed this at my book study.
I am sharing this so YOUR friend will not have to go through what I did. Tell him to smile and only answer question that are asked.