The fact that the units are the same does not make it acceptable to use an incorrect code - if you are knowingly submitting incorrect information that is not supported in documentation, you cannot say definitively that it is not a compliance issue because it is not possible to know how these codes will be ultimately be used by the payers. Although the reimbursement might be the same for the two codes, it could still potentially cause a financial error because different codes may have different coverage requirements, be in different benefit categories, or be reported differently for calculation of risk or morbidity. It is a risky practice to assume that incorrect coding is not a problem simply because the codes in question are of the same value.
What it the CRNA's rationale for wanting an incorrect code submitted? There is no valid reason I can think of for doing this. If the procedure was actually a vaginal approach, then the documentation should be corrected. If it is not, then the correct code should be used.