In addition to diffusing the mob at the jailhouse, Scout's decision to address Mr. Walter Cunningham in a singular and personal manner leads to another positive result.
In Chapter 23 not long after Bob Ewell spits in the face of their father, Jem broaches the subject of whether juries are really fit to issue verdicts fairly. He suggests that a judge, not a jury, should have the power to decide sentences in capital cases. Jem thinks Tom's trial was a disgrace. He mutters, "Tom's jury sho' made up its mind in a hurry." But Atticus disagrees,
"No it didn't."...That was the one thing that made me think, well, this may be the shadow of a beginning. That jury took a few hours."
Atticus reveals that there was one holdout who kept insisting that Tom deserved an acquittal. He was one of the men from Old Sarum, a "connection" to the Cunninghams. It turns out that Scout, Jem, and Atticus earned the entire Cunningham family's respect that night outside the jailhouse. So, "on a hunch" Atticus put one of their "connections" on the jury, thinking that perhaps this action would work in his favor. It was a risk, but it almost worked. For the Cunninghams left the jail that one night with "considerable respect for the Finches."