Corrected entry: When both of them go to the baseball game together, Ben's character sits down on her left side. When it cuts back he is sitting on the right.
Corrected entry: In one scene, in the airport, you can see a large microphone drop in rather obviously behind Ben Affleck and Jennifer Grey. I think it's when he's cajoling her to switch the roster.
Correction: The microphone behind Ben Affleck is actually a part of the movie. The operator is following a camera man that is there because of the airplane crash.
Correction: The second shot happens much later in the game. They could have switched seats at any time.