When an employee goes on FMLA leave, someone has to do the work. What if that someone easily assumes the employee’s duties and does a great job? Can you use that fortuitous realization as the basis for firing the leave-taker when he returns? Perhaps, but there’s a risk. The employee may sue, alleging the real reason he was let go was retaliation for taking leave, and not that you figured out the company could get along just fine without him …