I don't see the logic of intentionally omitting sugar in the video--and only sugar--if Luigi is actually using sugar in his sauce. The Stanislaus tomatoes are fresh-pack tomatoes that are naturally sweeter than most tomato products that you see out there, especially those made from concentrates, so it wouldn't surprise me that someone used to regular (non-fresh-pack) tomatoes that they might get at their local supermarket might find Luigi's sauce sweet. The only way to know what effect the herbs, grated cheese, etc., has on the sweetness of Luigi's sauce is to reverse engineer it to find the percents of those ingredients used.
I have learned to pretty much ignore terms like "sweet", "salty", "chewy", "crispy", "cracker-like", "thin", "thick", and so on. They mean different things to different people.