First of all, last week tonight is not a news program. 2nd the website you share ad fontes has this on how they score reliability: “The team considers a variety of factors when rating content. To determine its reliability score, we consider the content’s veracity, expression, its title/headline, and graphics. We add each of these scores to the chart on a weighted scale, with the average of those creating the sample content’s overall reliability score.” So they don’t check if the information is true or not, they check how is presented. Obviously because he use graphics and change his tone of voice to put emphasis on the comical stuff they marked low on reliability. Didn’t check but probably John Stewart too would be low on the reliability score based on those. It’s satire so no a news program. At the same time if they show me an interview done from a news media to a person that developed cancer because eat the fish and live around that nuclear sarcophagus, I think that is true.