They're wrong. :-)
This answer does not make me your attorney. My answer was only intended to provide general information and cannot be construed as legal advice. No attorney can offer advice without detailed background information which may reveal hidden issues and concerns impossible to anticipate in this format. This response does not establish an attorney/client relationship. I do not check this website regularly, so I may not respond to further postings here. I strongly advise the reader to seek the counsel of a qualified attorney or consult a legal self-help center in their local jurisdiction as laws, rules, and procedures vary from place to place. IRS CIRCULAR 230 DISCLOSURE: To ensure compliance with requirements imposed by the IRS, please be advised that any U.S. Federal tax advice contained in this communication (including any attachments) is not intended or written to be used or relied upon, and cannot be used or relied upon, for the purpose of (i) avoiding penalties under the Internal Revenue Code, or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.
It does not matter where you got married if it was a valid marriage where you did get married. You could have been married in Las Vegas, New York, Paris, London, or anywhere else. It is still valid.