Sunset launches result in this phenomenon:
This was a recent Vandenberg launch near sunset, the picture taken from San Diego, though similar sights were seen as far away as Phoenix and Tuscon AZ. There was no after sunset displays in the sky on that evening, I certainly would have noticed as I was driving that direction. So to add to the 'mystery' of this being a missile, it produced no upper atmosphere contrails, meaning it would have had to go into a ballistic mode at normal commercial aviation flight levels.
I know the admiral in charge of the western pacific. If he even suspected that there was a submarine launching missiles in his neck of the woods, he'd throw everything he had into searching for it, and if ordered to do anything else, would be in front of a television camera within minutes to expose it.
Thousands of private pilots, thousands of boat crews on commercial and private ships, hundreds of commercial aircraft pilots, air traffic controllers, the AF Space Command in Los Angeles, Port Huneme Naval Base, Edwards AFB, Vandenberg AFB - no conspiracy survives that many people (not to mention the millions in Los Angeles who somehow missed this as well...)