Continuity mistake: When Roscoe comes out of the courthouse he runs into the potted tree, he grabs it, and starts to fall over to his right. In the wide shot, he falls over to the left and down the steps with the tree.
Continuity mistake: When the boys have Emory Potter in the car from his wedding in Lake Chickamahoney, they go off the paved road cross-country. As they go, you see they are on a dirt road. The hit a hump of dirt (almost a convenient ramp) and they go flying. As they do, the area suddenly goes from wide open country to a paved road with a wooden fence, and power poles lining it.
Answer: Various reasons, but mainly to drive the Dukes out of Hazzard County because the family have been foiling his schemes since his and Uncle Jesse's bootlegging days.
Captain Defenestrator