As I understand it, she kept dragging her feet delaying the return of the signed contract. Considerable office/secretary time and long distance phone calls finally prompted her to send it back. He is extremely busy this time of the year, and, of course, he couldn't book that date with anyone else, so, she has screwed him out of his fee. Her only excuse was that there was another performance of some kind that same night. Well, she should have known that from the start.
He is too gentle to go the legal route, but, I would!