I'll third Lawanna's advice. I have done CPR on a koi by swishing it back and forth through the water, making sure the mouth opens and the water flows through the gills. That's the manual way; believe me, Lawanna's way is much easier! And there is a better success rate.
Koi will always want to go back where they came from. Using pond water would have helped, but not by much. As Kat said, a net cover is usually required to keep them from jumping out. Ditto on the predator thing.