I'm not reading any "conspiracy theories" into this. Cops hate cop killers. They really hate cop killers that try to drum up public support for their cause. Most of the time they'll stop at nothing to get them. If that means outright kill them by whatever means, so be it. This was a bad cop gone off the rails. He was stupid or he could have easily done more damage. The LAPD has terrible public relations, no doubt. And the longer this went on, the worse it could have played out for them. Now they look like heroes who stopped a madman. At least that's the way the media will play it, and most people will accept it.
They used "Burners", (Pyrotechnic tear gas canisters), on purpose. They knew it would cause a fire. They knew he would most likely put a bullet in his head rather than burn to death. That turned out to be a better public relations outcome, than if he rushed them, and they shot him 60 times. This guy set himself up to the point the cops could do pretty much anything they wanted to get him. Once he killed the Sheriff's deputy and wounded yet another, all bets were off.