Question about the ending?

Yeah I was wondering that too, there didn't seem to be any continuity behind it, perhaps complications arose where they realise they didn't love each other through the whole hardship or some *beep* but I think more than anything it was just to show all of the damage the girl did so she could feel guilty at the end. Horrible ending. An interesting commentary on the world the liberals created, a girl can let out a racial slur and make statutory accusations and get famous.

I think she is a very interesting character, and even more so because she is in the movie so little. In the birthday dinner scene, we see that she is possibly spoiled/conceited (she said she was starting to worry that he didn't get her anything, and then she seemed disappointed that it was just a little skirt). She also is apparently distant from her husband, since she was ackward about changing in front of him.

When she begins her schoolgirl act, she seemed to think it was a great joke at first. She thought that the similarity of her new skirt to the uniform skirts was a coincidence. The first tip off that it was on purpose should have been the 'naughty' essay he had her read, however it is unclear what her reaction to that essay was.

Assuming she didn't read too much into it at the time, we have to wonder what her thoughts were later at the trial when it becomes a piece of evidence. After all, schoolgirl fantasies are fairly common, but fantasies about a specific schoolgirl, especially when she is claiming sexual molestation, would be hard to take as a wife. She actually would have been an invaluable witness for the prosecution had she come forward with her story.

So, based on what I have assumed above from her character, she is a woman who is self-centered, with a husband who is only sexually aroused when she is pretending to be someone else. This seems to be plenty of reason for her leaving him. It's not because of the girls' accusation, but because of the origin of the letter which came out during the trial.