Poppycock! A summons or subpoena most definitely does not trigger a SAR filing, and you certainly cannot cite the receipt of a summons or subpoena in a SAR as a reason for filing.
If, during your research of records to comply with a summons or subpoena, you discover customer activity that appears suspicious, THAT activity would trigger the potential for a SAR, whether the account has remained open or has been closed.
I wonder if the examiner was saying that the receipt of the summons/subpoena should at least trigger an investigation into whether a SAR should be filed. Even if so, I think that is a stretch.