8 C.F.R 204.5 allows an applicant who has

multiple approved petitions to use the earliest priority date.

Ur Lawyer should be able to explain in the cover letter that the carry over complies with the 8.C.F.R. Discretion of the DAO or clerk of the USICS office does not afford them any power over the law.

http://www.uscis.gov/propub/ProPubVAP.jsp?dockey=7ff6c6895fc16b7c7a9154ec1a793007

Disclaimer: FYI only, not a legal advice.