The Eagles were finalists (the only Mississippi school to be) and when Dupree left Oklahoma, he transferred to USM where of course he didn't play deciding instead to go to the USFL.
That he left Oklahoma becuase he and Switzer didn't get along, and apparently didn't realize the transfer rule saying that he would have to sit out a year, or he didn't want to sit out a year and then went to the USFL.
If you've never had the pleasure of reading this book, I highly recommend it. One of my favorite sports novels. Even Coach Sherrill plays a role in it (while at Pitt).