"I'm happy to go over these problems, review further, or answer any questions you want for the rest of the class, but since some people seem interested in leaving, I won't penalize anyone who decides to leave."
Within 5 minutes, the room is always cleared, no matter that a final or whatever else is coming. Which means I get to leave early.
Well, almost always. Occasionally there will be a small group of 2-3 who will stay, but then I just get to sit down and have a tutoring session, which is fun and easy. For the most part, everyone takes the opportunity to leave, with (I'm assuming) the belief that they'll just study "later".
For some reason, it always makes me think of Calvin's mom telling Susie that "it's mean to take advantage of kids with no common sense" when she finds Calvin about to eat five worms for Susie's nickel.