I’ve seen that done. The text involved was hot garbage. I stand by my statement that the professor in question was not qualified to write a textbook. Many people attempt things they are not qualified to do.
To get their average of 21 g, the people who did that “study” had to weigh a lot of people who were nearing death and then use only the readings they liked. If they had used all the data, they would have found that at the moment of death the average change in weight is approximately bupkis.
That was my first guess. It does leave this story arc without an end, though. Would the cartoonist really want to do that?