I understand the panic in your question. First, there IS something in the Cares act for you. If you have a federally guaranteed mortgage, you can apply for forbearance. Contact your servicer immediately. It was just announced that nearly 10 percent of mortgages are now in forbearance, so you’re not alone!
Here’s a link to all the info you need before you contact your mortgage servicer:
You are right, of course, not to dig into his 40l(k) unless as an absolute last resort. They have waived the 10% early withdrawal penalty (for people under 59-1/2) but he would still owe taxes on the withdrawal. And would miss out on all future growth tax-deferred inside the plan. BUT, he should look at his investments inside the plan, and now that the market has rebounded, maybe he should move at least half into the most conservative, stable value fund inside the plan.
And finally, have hope. This isn’t going to last forever! There will be jobs — maybe not the old jobs, but real opportunities in the future. He is only 50 — plenty of time to start a new life. So he should be trying to look ahead to were the opportunities will open up.