How does Scout diffuse the tension between Atticus and the Old Sarum bunch in front of the Maycomb jailhouse?

In Chapter 15, Jem and the children decide to look for Atticus and end up spotting him sitting outside of the Maycomb jailhouse reading the newspaper. As Jem, Scout, and Dill watch from across the street, the Old Sarum bunch arrives and surrounds Atticus. The children then move closer and hide near Tyndal's Hardware store. Scout listens as Atticus tells Walter to leave and Walter responds by saying that they called Sherriff Tate off on a snipe hunt. After Walter says, "that changes things, doesn't it?," Atticus responds by saying, "Do you really think so?" (Lee 93). Scout cannot contain her curiosity and runs out into the middle of the group of men. Everyone is shocked at Scout's arrival, and Jem slowly follows her out. Scout is unaware of the dangerous situation she has just entered and watches as Atticus tries to get Jem to leave. Scout then looks around at the circle of men and notices Walter Cunningham. Scout attempts to get his attention by talking about his son, Walter Jr., who happens to be in her class. Mr. Cunningham finally acknowledges Scout's presence and says, "I'll tell him you said hey, little lady" (Lee 95). He then turns around and tells the mob to leave. In the next chapter, Atticus explains to the children that Scout made Walter see the error in his judgment. Walter was able to put himself in Atticus' shoes and felt sympathy for the situation he was in.