I think it's a combination of things. Some California cops are out of control, and that's partly because of gang activity and the rich targets out there. Would they have shot anyway? Jeeze I don't know. I mean here cops have shot people in their driveways checking their cars, in their garages, in mistaken houses. A little 5'2, 105lb filipino woman holding a paring knife was shot 5 times in Costco.
Your premise does have some validity in theory, but then Ca cops have always been against open carry and long gun carry, even when it was legal and looked for ways to hook people up, stopping guys OC-ing who were walking their dogs, fer kristsake.