Lionel Carson was an old friend of Sarah Jane Smith.
In 2011, Sarah Jane met Lionel at the demonstration of the SerfBoard, where he expressed a dislike for modern computers, stating, "Nothing wrong with a typewriter says I". By the time that the demo finished, however, he had suddenly developed a liking for the SerfBoard, due to the hologram of Joseph Serf hypnotising him.
Lionel was also present at the launch for the SerfBoard, and met Clyde Langer and Rani Chandra, who were disguised as journalists for a magazine called Twilight Years for the over 60s. When Luke Smith and Sky Smith modified the hologram so it hypnotised the audience to destroy John Harrison's pen, Lionel stepped forward and smashed the pen underfoot, freeing the Skullions. (TV: The Man Who Never Was)