你叔叔去中国法院的时候隐瞒了他已经是美国公民的事实。中国法院对他是否有jurisdiction--你要问问中国律师。估计没有。
即使中国法院有jurisdiction, 按照SMERDA v SMERDA, Ohio的法院会给出DECLARATORY JUDGMENT 认为你叔叔在中国的离婚无效。SMERDA v SMERDA没有被overturned, even thought it was decided in 1947, it is still good case law.
I think you will win the case.