I need more information to answer this question. What were the 9 discrepancies? Did they question the legitimacy of your marriage? Or, are they asking for more information in a particular area?
What were the areas of misunderstanding?
Discrepancies may occur in green card interviews for all sorts of reasons . If any of them involve the validity of your marriage, you should definitely hire a lawyer. You will need to assemble proof that your marriage is bona fide whether you file a Response to the Notice of Intent to Deny, or a new petition. Such evidence consists of affidavits from people that know you as a couple, jointly held property such as bank accounts, real estate, a lease, etc., and other things. I strongly urge you to retain the services of a professional; immigration lawyer to help you in either event.
If your petition is denied, you may refile another but, if the reason for the denial is that they did not believe that your marriage was legitimate, you will face additional hurdles.
I hope this helps, God bless you.
I think that the following links may be of assistance to you.
(213) 623-4592 x0 Mr. Shusterman is a former INS Trial Attorney (1976-82) with over 35 years of immigration experience. His response to your question is general in nature, as not all the facts are known to him. You should retain an attorney experienced in immigration law to review all the facts in your case in order to receive advice specific to your case. Mr. Shusterman's statement above does not create an attorney/client relationship.