Misrepresentations noted but for them moment put aside, an immigrant visa can be used this way successfully once or maybe twice. By the third entry, it will be very obvious the green card holder is not residing in the USA, and they'll be denied entry. The issue I see, is to wonder how they got past NVC to an interview. NVC would have wanted evidence of domicile in the USA, or the petitioner's intent to re-establish domicile. Neither would be truthful. Whether material misrepresentations or not, is a separate question. Please do raise these concerns with the attorney BEFORE the interview.