Looks to me like it's about point E. in the Mesa proposal (starting page 11), i.e. whether the move from Orlando to JFK was met with a agreement on completion rates (see Delta doc starting at point D., page 6). Delta goes as far as stating that the evidence provided in favor of Mesa by then COO Bates was fabricated, whereas Mesa simply states Delta dropped the ball on them regarding the formalization of an oral agreement between Bates and Boyd (the Delta counterpart).