No person under the age of twenty-one shall operate a motor vehicle after having consumed alcohol as defined in this section. For purposes of this section, a person under the age of twenty-one is deemed to have consumed alcohol only if such person has .02 of one per centum or more but not more than .07 of one per centum by weight of alcohol in the person’s blood, as shown by chemical analysis of such person’s blood, breath, urine or saliva, made pursuant to the provisions of section eleven hundred ninety-four of this article. Any person who operates a motor vehicle in violation of this section, and who is not charged with a violation of any subdivision of section eleven hundred ninety-two of this article arising out of the same incident shall be referred to the department for action in accordance with the provisions of section eleven hundred ninety-four-a of this article. Except as otherwise provided in subdivision five of section eleven hundred ninety-two of this article, this section shall not apply to a person who operates a commercial motor vehicle. Notwithstanding any provision of law to the contrary, a finding that a person under the age of twenty-one operated a motor vehicle after having consumed alcohol in violation of this section is not a judgment of conviction for a crime or any other offense.