I've chaired several appeal committees, and a few special committees.
The instructions from the WTS to appeal committees strongly indicates that they will, in the vast majority of cases, side with the original committee's decision. Also, if they feel that the original reason you were disfellowshipped was not satisfactory, BUT, in the course of the appeal meetings discover ANOTHER reason why you could be disfellowshipped, the dfing stands.
I've seen very few appeals be successful. Your father is kidding himself that it would have made much of a difference.
It's an insane, dysfunctional system which has nothing to do with any Biblical principles. In Israel, these matters were judged publicly and openly, in the city gates, and that sort of transparency in the Witness judicial system is very sorely needed.
S4