The rescission period does not begin until the last of three events:
1. Delivery and receipt of all material disclosures
2. Delivery to the consumer of the required rescission notice
3. Consummation of the transaction
I don't believe you can consummate the transaction, which includes a mortgage lien on the property to be acquired, until your borrower has the deed to that property (he can't pledge what he doesn't yet own). That could throw a monkey wrench into your lender's plan.
However, consummation of the transaction is determined under state law. You will have to consult legal counsel on when such a transaction would be considered consummated under Kentucky law. What makes sense to me isn't necessarily how state law will view the question.