Fiona is completely dedicated to Michael, but Michael is completely dedicated to getting his job back, no matter what the cost may be.
Fi isn't willing to stick around and watch Michael turn into someone she no longer knows or loves.
Michael sees Fi slipping away, but can't bring himself to say what she needs to hear to stay.
One of these days, though, it may be too late...
Please let me know what you think of the video =)