Well, things may have been different in the early 1980s. I wasn't a lawyer then. I wasn't even born then. But according to the criminal law now, there doesn't appear to be any avenue by which a prosecution of a passenger could be successful, even if the passenger was supervising the driver.
Care and control is established by the prosecution in two ways. Typically, a person is observed driving the motor vehicle. So the proof is relatively easy. In other cases, however, the vehicle is not being driven but there is some course of conduct that leaves the driver in "care and control" such that there is a risk to the public. There is a presumption in the Criminal Code that any person who occupies the driver's seat of a motor vehicle does so for the purpose of setting it in motion. That presumption can be rebutted by evidence to the contrary, i.e., evidence that there was some other reason to occupy the driver's seat or that the subject did not have the means to readily set the vehicle in motion.
The recent Supreme Court of Canada decision, R. v. Boudreault 2012 SCC 56, sets out the test for care and control of a motor vehicle. There, the Court wrote:
"For the reasons that follow, I have concluded that “care or control”, within the meaning of s. 253(1) of the Criminal Code, signifies (1) an intentional course of conduct associated with a motor vehicle; (2) by a person whose ability to drive is impaired, or whose blood alcohol level exceeds the legal limit; (3) in circumstances that create a realistic risk, as opposed to a remote possibility, of danger to persons or property."
In Mr. Boudreault's case, he had fallen asleep in the driver's seat of his vehicle while waiting for a taxi. The engine was running so that he could stay warm while he waited. A taxi, apparently, never arrived. Mr. Boudreault was awakened by police who commenced an impaired driving investigation. The Court found that given the steps he had taken to ensure that he did not drive, he had rebutted the presumption.
Another leading case on the issue of care and control is The Queen v. Toews,  2 S.C.R. 119, which states that:
"acts of care or control, short of driving, are acts which involve some use of the car or its fittings and equipment, or some course of conduct associated with the vehicle which would involve a risk of putting the vehicle in motion so that it could become dangerous."
Thus, it is clear that there needs to be some course of conduct associated with the vehicle itself that creates a danger. Sitting in the passenger seat, supervising the driver, does not meet this standard. There is no realistic risk in the circumstances of a supervisor and a passenger that the vehicle will become dangerous. And there is no use of the car, its fittings, or equipment by the supervisor that could in any way constitute a danger to the public.
So I disagree with what Mr. Schewe suggests in his article. The elements of the offence just cannot be made out on those facts.