How did the Scowrers get away from the court unpunished?

The Scowrers left the court unpunished because the evidence was not compelling, and the witnesses were unable to point anyone out... the descriptions they gave were too vague.

The magistrate could not possibly, on the evidence, have held them for a higher court. On the one hand the compositors and pressmen were forced to admit that the light was uncertain, that they were themselves much perturbed, and that it was difficult for them to swear to the identity of the assailants; although they believed that the accused were among them. Cross examined by the clever attorney who had been engaged by McGinty, they were even more nebulous in their evidence.

The injured man had already deposed that he was so taken by surprise by the suddenness of the attack that he could state nothing beyond the fact that the first man who struck him wore a moustache.