Scott Beach and Terry McGovern, members of the San Francisco improv comedy troupe The Committee, played the part of the two engineers torturing THX. They ad-libbed the dialogue for this entire scene; George Lucas told them to act as if they were running tests on electrical equipment, fitting with the film's theme that people are looked as as devices rather than humans. It was also either Beach or McGovern who ad-libbed the famous line "I think I ran over a Wookiee back there on the expressway" later in the film.
I met Terry McGovern once! He's also the voice Launchpad McQuack in DuckTales, and most especially, he played Mr. Wolfe in another Lucas film. One that sticks very close to me. American Graffiti.
It’s a great example of the dark humour of this film that instead of the brutal and dedicated thought police of something like 1984, there’s a load of slightly bored technicians in charge of the torture devices.
The irony is, the very device we're watching this clip on could very well observe & control us in ways only to be imagined. Let that percolate in your mind for a moment. Lucas postulated this 50 years ago.
Production Companies: Warner Bros. (current owner) Turner Entertainment (current owner) Semetoll-Imkerss Distributed Pictures (Distributor) Semetoll-Imkerss Production Studios (Presentation) American Zoetrope (production)