what would happen if he took his 150 and bought another home. one that is at current, cheaper prices, something like a condo in a heavily depressed area (np, mission valley, murrieta, etc). move into it and let everything else go (cc debt, investment props, etc). keep little to nothing, let it all go to repayment. negotiate a manageable repayment schedule for the rest and work for a living.
I don't think he won't be able to qualify for another loan, especially these days. I wonder if the problem is that he can't find renters. If so, I wonder if it would make sense to try to rent some homes as Section 8 housing. Don't know the exact details, but just brainstorming off the top of my head.
If he's headed for BK/foreclosure, I'd take the $150k and hide it somewhere with a trusted person, max out all CC's with cash advances and hide that somewhere.
One thing for sure. If he and his girlfriend are still together after this mess, I have to say that girl is definitely a keeper.