I am not expert, but accident scenes aren't what they seem sometimes. Intact airplanes (seemingly) w/ high impact speed and angle ( > 61 mph ) and their are no survivors. That 3 blade prop w/ one blade bent could have been at full throttle, 1 blade hit and the whole assembly liberated from the crank. Whatever it was, he didn't have power, out of options, and the last he wanted to do was hit a house. He'd have put in down on a street if he could have. Maybe one engine out, for whatever reason and or stall getting below VMC. Very sad, prayers for all those now dealing with loss and grief.
There’s a golf course about 2,000 feet from the crash site, running south to north. But if he was eastbound coming out of Fullerton he had just passed it. Maybe he stalled while trying to turn back towards it.