alex gibny, seen publicizing the film at the sundance film festival, stands by his sources. >> what'sressive me about the film was in telling the stories of these individuals that we profile, how smart, how savvy they were and yet they got inside a belief system that when they looked back when they got out, how did i get there? >> reporter: the hbo movie is by no means the first public relations challenge for the church. >> tom cruise signcientologist. >> reporter: there was this leaked video of tom cruise. >> i do what i can. and i do it the way i do everything. there's nothing partway with me. >>. >> reporter: this on-camera shouting match between a scientology spokesman and a reporter for the bbc -- >> end of the interview! >> the origins of the human race as described through the intergalactic emperor -- >> reporter: and this scene from a "nightline" interview in which that same church spokesman ripped off his mike and walked away when asked about the details of the religion's beliefs. the hbo thrill is based on the best-selling book "going clear" written by investigative reporter