You also don't just fall out of the sky like that on the final approach, especially in a lear. He was on IFR from the recording and you do that in shitty/ cloudy weather. So either he switched out of IFR too early, he wasn't paying attention to the instruments, or he had redundant failures when he switched to VFR on landing.
A lot of crashes are unique to California because of their rando winds due to geography and weather.