How does Johnny escape a whipping?

One day, British officers often pull Johnny aside and question him. One day, they threaten to flog him simply for walking his horse down the street and being employed by the Boston Observer. However, the soldier who is supposed to do the flogging, Pumpkin, helps Johnny escape by whispering to him to use his spurs. Johnny does so and Goblin bolts away, leaving the British soldiers in the dust.