27 CFR 771.72: After citation.

If a licensee or permittee surrenders the license or permit after notice, but prior to the referral to an administrative law judge and prior to an initial decision, the Director of Industry Operations may accept the surrender of the license or permit and dismiss the proceeding as moot. If a licensee or permittee surrenders the license or permit after notice and after the referral to the administrative law judge, but prior to the issuance of a recommended decision, the Director of Industry Operations may accept the surrender of the license or permit and shall move the administrative law judge to dismiss the proceedings as moot. In either case, if, in the opinion of the Director of Industry Operations, the evidence is such as to warrant revocation or denial of renewal, as the case may be, the surrender of the license or permit shall be refused, and the proceeding shall continue.