The N-400 may be rejected because he did not register. He should wait until he is 31 until he applies so this issue does not come up.
You may contact the Law Office of Robin J. Gray for further legal advice. Office (610) 689-0877; Fax (610) 689-0932; Cell (484) 769-5855; robingraylaw.com This answer is for informational purposes only. It does not establish an attorney client relationship.
There is a difference between REJECTION and DENIAL. His application may be DENIED (decision based on substantive grounds). Rejection is the process when a case is sent back based on a technicallity such as a missing required document, no fee attached, etc. When a case is rejected, the applicant can file again right away if he/she can correct the deficiency. Denial of a citizenship application is a different story. So yes, his application may be denied.
This answer is for informational purposes only and should not be construed as legal advice.
Did he check to see if he was registered by USCIS? You can go on the website and enter your information to see if your are registered. SSS.gov
Mr. Asatrian's practice is dedicated to the area of immigration and nationality law. Please note the information provided herein does not constitute legal advice and should not be construed as such by anyone. It should not be relied upon as legal advice as more specific facts, research and analysis may be required to formulate a proper strategy and action in your matter. Please note this does not create an attorney-client relationship whatsoever. You should seek the assistance of an experienced immigration attorney to review your matter thoroughly and gather all of the necessary information and documentation to provide you with the best possible legal solution.
He could be denied, but he could also take steps to cure this problem before applying. I've seen many naturalizations approved for people with similar facts who take corrective action first. Call a lawyer.