Answer to Civil Complaint was filed in the wrong courthouse?

I filed, pro se, a federal lawsuit against my ex-husband. There is also an eighth judicial circuit lawsuit pending against him. His attorney filed an untimely (late) answer to the federal civil complaint under the eighth judicial circuit lawsuit case number. I am in the process of putting in a Motion for Default Judgment, although it appears that the federal Judge accepted the Answer, even though it was filed late and has the wrong header on it. If there is an attorney out there, please advise. Thanks!