A bank's asset size is not necessarily directly related to its net worth.  Assets are all loans, investements (bonds), RE and personal property.  Those assets are offset by investor capital, customer deposits, brokered deposits, and borrowings.  At the end of the day their net worth impacts how much they are able to loan, both for individual loan relationships and total loans but it is not a direct relationship to their net worth.

These things are always surprises to the general public but I'll guarantee you it was not a surprise to regulators and bank management.  I can almost guarantee that there were previous "Memorandum of Understand" agreements between regulators and management.  A big issue right now revolves around mark to market accounting.  It does not apply to loans but does to other investments such as bonds.  Previously, banks were allowed hold bonds and not realize gains or losses until the bond matured or was sold.  Beginning in 2018 regulations changed and banks are now required to recognize these gains or losses each month.  Remember, bond returns are an inverse relationship to interest rates, and rates have skyrocketed!