Minsky was an unorthodox economist who didn't get much play, but when the global financial crisis hit, of course, people started calling what happened a “Minsky moment”. A “Minsky moment” happens when lenders discover that borrowers cannot repay their loans. In fact, they cannot even pay the interest on their loans.
Up until that point, the lenders are happy to continue to provide credit, in this case to the real estate market, but at some point they discover that many of their borrowers are about to default, and that brings on the crisis.
The stage that you are referring to is actually called the “Ponzi finance” stage, and it refers to when the lenders have to lend money, not just more money for purchases, but new money just so the borrowers can make the payments on their existing loans.