I don't know what the best course of action would be. Some say "SSS" (shoot, shovel, shut up), but I'm not inclined to do that. My initial thoughts are:
1. You better make sure that it's a cut-and-dried case of self-defense before you shoot. If you shout at it, or throw stuff at it, and it doesn't leave, get ready to shoot. If it charges, fire away. Distances come into play here, though, and it's all going to come down to a judgment call. As one person wrote, if it doesn't run away when you yell at it, it thinks you're food!
2. If I were to shoot one in self-defense, I think I would call the DFG and tell them that I had shot a lion in self-defense, and respectfully decline to answer any other questions until I had consulted with legal counsel, at which point I would cooperate fully.
The DFG is not going to look at it objectively. They are going to over-zealously prosecute every single infraction they possibly can, whether it was real or not. They are not in the business of treating you fairly. Tie does not go to the hunter. That's why many people say "SSS". I say, treat it as if you had just shot a human in self-defense. Report the incident. Don't try to cover it up, don't lie, and don't talk to the police (or warden)- let your lawyer do that. If you think that being cooperative and just answering all their questions is going to make it go smoother, and will save you legal fees, and keep you from being prosecuted, think again.
Yeah, it's....unfortunate (I can think of stronger words)...that lions are given god-like status in this state, and that we would even have to think twice about defending ourselves against such a dangerous predator, and that hunters are now the bad guys.