I am familiar with most of the laws there, that is why I do not take any weapons there. All my handguns have threaded barrels, as do all my ARs, and 2 are SBRs as well. I decided a long time ago I didn't want to try to keep up with their BS to try and stay legal. I am a very evil person in their view.
The arrest was stated as being for a loaded handgun in vehicle (illegal for him as you cannot have CCW as a non-resident and NO reciprocity) and high cap (>10rd) mag. He also went on about it being illegal to arrest someone for a misdemeanor. You CAN be arrested for a misdemeanor if the offense is witnessed by the arresting LEO. AND there are a few misdemeanors that REQUIRE an arrest, many of them gun related...like carrying a loaded weapon in a vehicle.
He stated he was uneducated on the laws in CA. And then goes on and on about how this was illegal and that was illegal. He needed an edumacation. And he is likely getting one...