If the work is being finished on 02/21/09, the documentation should be available to the lender in time to close. Someone might have to expedite the movement of paperwork (as in driving to the office of the termite treatment vendor and picking it up). There usually are additional conditions to be satisfied immediately prior to closing, such as approving the HUD-1 Settlement Statement. Therefore, Underwriting is expecting to do a last-minute review of the case. Adding the termite documentation should not be a problem.
If it is any consolation, be aware that practically EVERY real estate transaction has at least one last-moment issue which pops up. As long as everyone stays cool and factual, most are resolved with a minimum of delay to Settlement.