Unlike all of the other American Idol winners (Kelly Clarkson, Ruben Studdard, Fantasia Barrino, Carrie Underwood, Taylor Hicks, Jordin Sparks, and Kris Allen), season 7 champ David Cook was curiously absent from the show's May 26 finale in Los Angeles, which also marked Simon Cowell's last episode. Simon is leaving Idol to launch a U.S. version of The X Factor. But David tells In Touch he had a great reason for missing out on the festivities: The singer was participating in a golf tournament benefiting The Shadow Buddies Foundation, a charity that helps kids with cancer, in Kansas City. (David's older brother, Adam Cook, died of cancer in 2009.) And although David couldn't wish Simon a face-to-face farewell, he appreciates all the constructive - if sometimes caustic - criticism the judge provided on the road to his win. "Simon Cowell was a major help to me throughout the Idol process, and his advice and critiques served me well since," David tells In Touch exclusively. "I want to wish him the best in all future endeavors and look forward to seeing his continued success."