Dear Geist,
of omitting that comma?
Dear Judy,
was not the comma itself, but the construction in which it did not appear:
The canning, processing, preserving, freezing, drying, marketing, storing, packing for shipment [no comma] or distribution of:
(1) Agricultural produce;
(2) Meat and fish products; and
(3) Perishable foods.
If the house preference of those who wrote up the law was to omit the serial comma, a careful reading would have indicated that a comma was needed in that particular spot, to avoid the ambiguity that led to the court’s decision.
Sometimes it goes the other way. For example: “Those attending included the solicitor, Ms. O’Riley, and Mr. Singh.” Is the solicitor Ms. O’Riley? If not, the meaning would be clearer if the serial comma were omitted here, even if the house style preferred it in general. And one could argue that the best solution for both this example and the one in the Maine lawbooks is to reword the whole sentence.
Good writing and editing have to do with internal clarity and consistency, not slavish adherence to “rules.”