Hollywood actor Patrick Dempsey was left startled on a plane when fans of TV show GREY'S ANATOMY mistook him for a real doctor. The heart-throb, who plays DR DEREK SHEPHERD in the medical drama, was expected to step in when a passenger collapsed - even though he is only a doctor on-screen. Dempsey says, "They did the whole 'Is there a doctor on the plane?' thing and looked at me like I was going to respond. I was like, 'No, I'm not really a surgeon.'"