Why do Helena's coworkers dislike her in the novel, The Joke?

Helena's coworkers don't like her because she took a firm stand against an extra-marital affair happening in her office. A married man was having an affair with another girl. His wife turned to the committee for help, and the indiscreet party agreed to cease their affair. However, when Helena found out the affair was still going on, she took a stand. She believed the man was lying to the Party.