The money was lent against the house...not the balance of the checking account.
Technically the money was lent to the person for the purpose of purchasing the house. The house was pledged by the person as repayment of the loan should he default.
There is a significant difference in that as the money was not lent to the house but to the person.
The person is responsible in repaying, not the house, therefore any defiency in repayment can be imputed to the person as income. Ask the IRS. The defiency does not follow the house, it follows the person.
The monies given to the person is theoritically put into his bank account, where he has access to it to pay for the purchase. This is true even in escrow. Therefore the account where the monies went is also a part of the transaction and can be attached accordingly. especially if it is found that monies were used inapproiately or found monies were to travel through the account(s) of that person.
This is even true in bankrupcy cases where money was suddenly found to travel through those accounts at a later time, even if it were from lottery winnings, they can be attached to repay inapproiately cancelled debts.
As mentioned previously this is a very grey area and is subject to the interpretation of the courts for the final say.
Anyone wishing to deal in the grey areas of the law of course are welcome to do so, but be prepared to have a court in one area decide one way while the courts in another area will decide in the other manner.