I would like to stress that, the RD in the APPROVAL notice is the ND in the RECEIPT notice.
The lawyer is right in the sense that he/she reads the approval notice received and enter the information from there, which is actually ND for I-485 receipt notice. Who, even the lawyer, will bother to fetch out the one year old (or longer) I-485 receipt to confirm the RD/ND issues? Plus, they are very BUSY. Only applicant himself will care and remember his RD against his ND.
Hope this clarifies the confusion.