I have always wondered.Since the first episode Wes told Casey that she was not athletic nor smart.During the selection process Wes asked Casey what have happened during the trials and why did she perform poorly.But still there were a lot more girls left,if I can recall Linette and Diem were some of the girls that were left,who were probably more athletic than Casey.The only other evidence I have is that during the Fresh Meat after show ,Shane mentions that Wes told him that he was really digging that chick(Casey) and Shane encourage him to pick her.But still why would he?I do not get it.Did something behind the scenes happen that most people don´t know?