Rare photo of the ‘end’ of the rainbow

We received several storm photographs from readers Saturday, including one that depicted something that’s very, very rarely seen, especially in Southern California — the end of the rainbow
Several readers have said in the Comments section that they think this image was PhotoShopped. Nick: But it appears that this image is genuine. I have now had it reviewed by 7 people — 3 veteran photographers, a top-notch graphic designer who specializes in PhotoShop,m and 3 meteorologists at the National Weather Service. We also uploaded the image to Flickr and checked the lat/long of the image, which was taken with an iPhone. The info box says the photo was taken where the reader said it was taken. And the info text says the photo was not manipulated.
The photo was reviewed by: photographers Jebb Harris, Michele Cardon and Nick Koon, graphic artist Rick Ho, and meteorologists Mark Moede, Stefanie Sullivan and Brandt Maxwell. I’m stating these names for transparency.