That actually depends on the jurisdiction and the specific loan terms! For example, in California, mortgages are generally non-recourse, which means that the lender can take back the collateral (the house) upon default, but can't go after the borrower's remaining assets or property to make up any remaining deficit after liquidating the house.

That said, in this case you're correct: the article's subjects live in Colorado, which does not allow non-recourse mortgages.