If prices go down or stay flat it doesnt matter to him. Its his home and its cheaper than rent. At some point in time prices will go up simply because of long term inflation but that is not part of the equation for him. He is very settled in to say the least.
As for the recourse loan, there is essentially no such thing on a 1st TD even a cash out refinanced 1st TD. California is a one action state and if the lender forecloses they cant pursue a deficiency judgement. NOw 2nd TD’s are another matter.