(CBS) When Ashlee Simpson ran off the "Saturday Night Live" stage last week after her lip-sync gone awry, 60 Minutes cameras were there to record her embarrassing exit, and the reaction from show creator Lorne Michaels and other shocked SNL staff members. The exclusive of the incident will be part of a Lesley Stahl report about the making of the venerable comedy program, to be broadcast on 60 Minutes, Sunday, Oct. 31, at 7 p.m. ET/PT. In the now-notorious flap, Simpson had performed her hit single "Pieces of Me" without incident earlier on the show. When she came back to sing...