The on-camera relationship between Charles Luther (Gene Simmons) and Jack Ramsay (Tom Selleck) is one of intense emotion. "While we're playing a scene I hate his guts", Simmons said of Selleck and added, "I really want to kill him. It's funny, when doing this stuff it all wells up. I can't concentrate on giving somebody a certain look for an extended period of time without my temperature rising and my emotions starting to boil. Sometimes I would make up stuff about Tom, little things that would irritate me. And afterwards, I would go up to Tom and say, 'Look, I don't know if I was too . . . and he'd interrupt and say, 'NO, no. Don't explain anything. You're doing great'."

An assistant director came up to Gene Simmons during the location filming and said that one of the off-duty Vancouver police doing crowd control had pointed at Simmons and said, "better get him outta there". Upon being assured by the assistant director that he was one of the actors, the cop continued, "I don't know . . . if I shook hands with him, I'd count all my fingers".

Star Tom Selleck said of this movie's story around the time before the film was released in 1984: "Though it's set in the future, the film has a contemporary feeling. I suppose that's because the robots in it are technically advanced, but not that far from what we read about in the paper almost daily. The robots in Runaway (1984) are types which we're likely to see in factories, offices, and homes within the next few years".

The film accurately predicts domestic robots, video mail, social media, the Internet, voice-activated computers, biometric security (retinal identification), camera drones, tablet PCs, wireless headsets, and that police officers would use semi-automatic pistols as sidearms (in 1984, most police officers used revolvers).

Gene Simmons, in his book "Sex Money Kiss", said that director Michael Crichton's casting of him was based primarily on an audition where Crichton asked Simmons to stare at him for about a minute without making any facial expressions. Apparently, Crichton decided that Simmons looked menacing enough and cast him for the role of Luther.