Brown is D airspace. IFR and VFR is not separated, only traffic information is given. Large volumes of airspace in SoCal is E. So you'll find IFR traffic under ATC control in areas where VFR doesn't even have to announce their presence. Lots of people enjoy the benefits of open and accessible airspace. But it comes with risks.
Purely for information purpose. I have no idea about the circumstances in this event.