The purpose I saw in the character was Jamie enabled Cliff to have a chance at gaining majority ownership of Ewing Oil. Had the invalid document that Cliff and Jamie assumed were still valid been just a document between Jock and Digger (supposing there had been no Jason and therefore no Jamie) Cliff would have thought he had a chance at getting half ownership of Ewing Oil. With Jamie in the picture, and by marrying her, Cliff stood to control two thirds of Ewing Oil! It was a fun storyline. I liked the Wallace Windham character. He was a cool old guy and his testimony proved invaluable. It was also quite entertaining to hear him say that he met Digger just two or three times and he thought Digger was drunk every time, while Jason did all the talking. Fortunately for Windham, "Jason was greedy and stupid so he sold me their shares for a very low price."