I'm not really certain, since it's been a while since I've watched it, but:
I thought that in Part II, Michael tells Tom that he's "out" as consiglere, but he would stay on to look out for the family legal interests as they try to get "legitimate." Now I guess that there is always a possibility that Tom could implicate himself, but I feel that that aspect was supposed to be forgotten, and that we were meant to see Tom as an attorney only. Let me know what you think.