I don’t know one way or the other. He’s innocent until proven guilty. If what he says is true then charges will likely be dropped.
I doubt it. California is pretty zealous about enforcing their voluminous, arcane, and vague gun restrictions.
This has become a political case. It may make a good test case to take to the Supreme Court. A Federal judge has already ruled the California ban on firearms for non-residents is unconstitutional. However, the final judgement in that case in not yet approved. (Settlement under negotiations).
California gun laws are very restrictive. Essentially, you cant possess except where the law provides exceptions. Exceptions include in your home or at a range for example. Transport is a PITA because you can only transport between places you can legally possess, and when transporting the firearm is supposed to be unloaded and in a locked container (a trunk counts but a glove box does not in CA). Legally you cant even stop at a convenience store on your way home from the range. So lots of little PITA gotcha’s if a prosecutor wants to make something of it.
LEO’s and retired LEO’s have tons of exceptions to the above. I thought I saw one report that said the person involved may have a LEO background. Not sure about that. CCW holders also have exceptions. Thats good if you live in a county where your sheriff will actually let you have a CCW. Almost impossible to get a CCW in many counties in CA.
So unless he qualifies under a LEO or some other exception, CA law may say that he transported to a place that was not legal to possess (the rally).
I have been out of commie CA for many years now so my info may be dated, but I dont think much has changed, at least not for the better.