Let me get this straight: You notified the borrower they had to get insurance on 10/1/16 (or shortly after) and now you have a LOMA dated 12/1/16? If that's correct, you may have had a small window of time that should have required insurance (45 days after you notified them), but not you know they don't need flood insurance. IOW, there may be a technical violation for not force placing during that window (11/15-12/1 at the most). I would let it go.