If you mean has an appeal committee ever overturned the original committee's decision (to DF), then the answer is, Yes.
I was on an appeal committee that overturned the orginal decision because it was clearly without cause. It involved a 17 year old girl, living at home w her parents, who had a boyfriend (a young JW man in the same congo). Her parents were not invited to the original committee "hearing" at which the elders told her she should stop "dating" the boy because she was too young to marry and because her parents had indicated they were opposed to any such marriage. The girl, naturally, let a little attitude show and said there was nothing wrong with seeing the boy, she was indeed hoping for marriage at some point, and, besides, she was almost 18. They DF'd her because of her attitude, "brazen disregard for counsel of the elders," or some such nonsense, under the heading "loose conduct." [By the way, "loose" conduct always sounds like hanky panky was involved, but in this and many other cases, it isn't]
Given her age, the appeal committee asked her parents to attend. At the hearing, they testified that they really weren't that opposed to the relationship but had simply asked one of the elders for "guidance" concerning whether she was old enough to enter a serious relationship. They were very surprised when their daughter came home disfellowshipped.
We corrected what was clearly a miscarriage of "justice" (JW judicial committee + justice = oxymoron). The original committee members were very displeased, and two of them went out of their way to avoid any contact with us at future circuit and district conventions.
All too typical of what happens when you put that much power into the hands of "untrained volunteers" (to quote J.R. Brown).