It invalidates by twisting. Rhetorically speaking it's simple to make the biggest in some class seem to be worst in some related class. If I'm the biggest taxi

It invalidates by twisting. Rhetorically speaking it's simple to make the biggest in some class seem to be worst in some related class. If I'm the biggest taxi operator in town, I'm likely to have the highest CO₂ emissions of all the taxi companies, see? You can omit or deemphasise the connection between the two and make me seem bad. It's just a form of lying by omission.