Innocent or Guilty

S1, E10: Hank wants Uncle Jack, the oldest member of the circus crew, to retire. After a fire happens at the big top, one of the crew finds Jack's pipe and Hank thinks that it was his carelessness. So Uncle Jack and his dog run away. When they get the new canvas for the circus, Ernie discovers that cinders coming from a nearby lumber mill, which made small burns on the new canvas, were the cause of the fire, not Uncle Jack.