Cruz, indeed, filed one set of publically available documents. Nothing was hidden from the public. You properly used the word "liabilities". When you borrow money covered by securities you own you don't necessarily call the money a liability. I can "borrow" money from my 401K. The interest I pay goes back into the account, along with the principle. I am borrowing money from myself. I wouldn't call that a liability.
Bottom line he hopefully fully collateralized those loans.