EIC & State Court Order

I have a friend whom I did taxes for, she has Abby full time (12 months) in her home and I had claim the EIC in her taxes.  The problem now I having is her ex-hushand is trying to claim Abby as an Dependent which he is allow to as court ordered, but he trying to also use EIC.  I told him it's illegal for him to try and use the credit as Abby doesn't live with him.  I found alot of information everywhere saying it is illegal for him to use EIC as it's tax fraud.  Am I correct?

 

So she also has another child which she claim on her taxes as Dependent which we have no problems with.  I have Abby listed as EIC only because she lives with her mom full time.  I understand no state court order can over ride EIC.