The show was scheduled for Friday night. Organizers say at 8 PM that night, they got word Amy had taken ill in England and was unable to make the trip to a city outside Paris for the festival.
So you hire Amy Winehouse and you actually rely on her showing up. You fall for the "taken ill" excuse. Amy can present a mound of evidence showing no one with even a reality-show-contestant IQ would rely on her promise to appear as scheduled.
After the jury throws the case out the window, we expect they'll all get wasted with her.