What does Julia say happened to one of her past lovers, and why does she consider it a good thing?

In book two, chapter three, Julia and Winston meet again in a ruined church tower in an abandoned part of the countryside, where she elaborates on her background and tells Winston revealing information about herself. Julia explains to Winston that she was chosen to work in the Pornosec department because of her impeccable character. Julia goes on to tell Winston that she engaged in her first affair when she was only sixteen with a sixty-year-old Party member who ended up committing suicide to avoid arrest.
Julia considers it a good thing that her former lover committed suicide because he would have surely mentioned her name during his confession. If the sixty-year-old Party member would have been arrested by the Thought Police, he would have told on Julia, and she would have been subjected to the same torture. Julia then explains to Winston why she continues to engage in affairs with Party members and elaborates on her hatred for Big Brother.