Absolutely. The IRS is controlled by federal law, and federal law trumps state law and state court orders. Too many divorce attorneys and judges don't understand this.
A noncustodial parent can only claim a child dependent if they have a signed release form from the custodial parent.
The only exception is certain divorce orders signed in 2008 or earlier that contain highly specific required language.
Even with a signed release form or a qualifying divorce order, the noncustodial parent is only ever allowed to claim the dependent exemption and the child tax credit. The ability to claim EIC, file as head of household, and claim the dependent care credit, always stay with the custodial parent, and can't be waived, transferred, or released.
