Your quantitative "mind" lacks initiative. The standard drink measurement on myriad websites is a 12 oz. beer = 5 oz. wine = 1.5 oz. liquor (80 proof). This is true for the Alcohol Help Center’s online “blood alcohol calculator" referenced in the article. A standard drink is defined the same way on the National Institute on Alcohol Abuse and Alcoholism website, also referenced in the article. The answer can be found by clicking on the link labeled "What Is A Standard Drink?"
Ergo, the unit of "a drink" is well-defined. Reporters aren't required nor expected to account for each reader's laziness quotient, especially one with a doctorate in physics. Purportedly. That claim has not been well-defined.