WHAT WOULD YOU DO 2-7 A Great Job

You have just finished an income tax return for a large client. In preparing the return, you noticed they overpaid sales tax on some purchases and were able to file for a huge refund. That plus the efficiency of your work resulted in less billable hours than budgeted. Promotions are around the corner and a significant component of your evaluation will be the billable hours over the past year. Other than yourself, if you added some hours, nobody would ever know. What would you do? And how do you rationalize your choice?