I am fairly certain you have rather large specimens of hitch (Lavinia exilicauda). As you noted, the peculiarly shaped and sized caudal fin coupled with the upwards pointing terminal mouth and anal fin proportion really offers a positive identification. Interesting what species can travel through the aquaduct, isn't it?
I will have to agree with others, you should never kill or keep species that you cannot identify. When you first killed the fish, did you know whether they were Sacramento splittails, Tui chubs, Arroyo chubs, or California roach? These rough fish species aren't commonly identified by sportfishers, and the awareness needs to be made that despite the lack of sportfishing status, many species of Californian roughfish are protected. It's important that fishermen do not contribute to their diminished population.
Additionally, I highly doubt whether any fish without a labyrinth organ could survive for over an hour out of water. While the fish may have swam away, it does not mean anything in terms of long term survival. I would recommend if you intend on releasing any fish, to NOT allow it to sit out of the water for over an hour. It just makes no sense.