Dang. You got it down.
His character was the first hint that some people still on earth were there because they didn’t have a choice. ONe of the frustrating things about that movie was some of those issues were never fully resolved and you were just left to your own imagination to write huge parts of the back story.
William Sanderson, the actor who played J.F. Sebastian, is one of my favorite character actors. He was great in Last Man Standing, Deadwood and tons of other roles I can’t think of right off.