How did Jeffrey make John McNab look bad?

Jeffrey made John McNab look bad by exposing his weaknesses and shortcomings in a public setting, highlighting his failures in a way that undermined McNab's credibility. This could have included revealing mistakes he made or contrasting his performance unfavorably with others. Additionally, Jeffrey may have used clever tactics or persuasive arguments to sway opinions against McNab, further tarnishing his reputation. Ultimately, these actions contributed to a negative perception of McNab among peers or the audience.