I didn’t rewatch “Cops and Robbers”, but I’ve seen it recently enough to have a pretty good memory of it. This was the last episode broadcast during the second season of I Spy. I agree with your assessment of it Aujouret, and don’t really have anything to add, except for some mostly irrelevant details.
The salesman who sells Kelly and Scotty the tape recorder is played by James Seay whose honored place in the pop culture pantheon was secured by his role as Kriss Kringle’s doctor/gerontologist in “Miracle on 34th Street” and as the guy (also a doctor I believe) pierced by the giant hypodermic needle in “The Amazing Colossal Man”.
I didn’t find much information on Hazel Medina who played Scotty’s sister Jo. She comes across as very likable in “Cops and Robbers”. She did appear in an episode of The Cosby Show called “Cyranoise de Bergington” in 1988.
There also isn’t a lot on Rupert Crosse who played Jim Brown’s colleague Chester. He was nominated for a supporting actor Oscar for his role as Ned McCaslin in The Reivers in 1969. There is a note on IMDB which says he was an old friend of Jack Nicholson, and Nicholson wanted him to play his buddy ‘Mule” in The Last Detail. Unfortunately by then Rupert Crosse was too ill to play the role. He died in 1973.
I’m pretty sure that in Robert Culp’s Spyfest interview, he makes the statement that “Home to Judgment” was the only episode in which members of Kelly’s or Scotty’s family are shown. Clearly he forgot about “Cops and Robbers”!