Why did the "Lynching Bee" fail?

The crowd travels to Sherburn's store and rips down the front fence. They halt when Sherburn emerges with a shotgun and calmly stands in front of them. He lectures the mob on how pathetic they are, tells them they are being led by half of a man, Buck Harkness, and calls them all cowards. When he finishes his speech, he cocks his gun and the crowd runs off in every direction.