Since buying real estate got him into this mess, the obvious solution is to borrow MORE money and buy MORE real estate. That has to work!! Cuz you know, real estate is NEVER a bad investment. All the guys in my real estate office tell me so.
(One factoid that’s missing is which property is the security for the HELOC? Doesn’t seem any of them have equity, I wouldn’t be surprised if when he tries to stupidly borrow more money, he’s told that well is empty. If it’s on mom’s house, why would he do that to mom? Put her upside down property even MORE upside down? Bad boy!!)
On a more serious note, that scheme put together by his RE friends has way too many ifs in it. Short sales and loan mods aren’t easy. You can’t assume any of them will happen. The opposite is more likely.