One thing I think they got wrong in GF II is having the scene at the Senate hearings where Tom was allowed to act as Michael's lawyer. If you look on the posters they have behind the Senators they have a breakdown of the family with Tom listed as Consigliare(sp?). I would think that not only would they not allow Tom to act as Michael's lawyer, they would have required Tom to testify under oath on his own.
I am not a lawyer, and my only experience with the procedures of law is being a faithful viewer of Perry Mason, so with that said, allow me to make this post.
First of all it was just a hearing, not a trial, and I think procedures are a little more lax. Also I would imagine that at that point, Tom was not convicted of any crime, and as such, most likely wasn't disbarred, and still able to practice law.
