In a 1999 episode of 'Cosby' ("My Spy"), Hilton Lucas sang the praises of the TV show 'I Spy'. And then he had a dream in which he was teamed up with Kelly Robinson. As in the TV show, Robert Culp played the role of Kelly Robinson in the dream.
It's a big Zonk, but I think I may have a splainin for it.
We can blame UNIT. In the past I've postulated that UNIT needed to protect the secrecy of the Gallifreyan Time Lord who was working for them at the time. Known only as the Doctor, he was UNIT's technical/scientific advisor. To help quell the inquisitive, UNIT decided to hide this alien in plain sight, by making him the main character in several 'Doctor Who' movies which they produced. For Toobworld, those two movies starring Peter Cushing would be movies as well. They must have proved popular enough to spawn a TV series, just like in the real world, because we saw many references to 'Doctor Who' over the years since then, and even sometimes scenes from the actual TV series as well. Once again, UNIT may have seized security camera footage and/or hidden camera footage and then incorporated into this TV series with the intent of claiming that it was all staged. They even hired actors who bore an incredible resemblance to whichever incarnation of the Doctor was seen on that footage. Examples can be seen in episodes from 'Extras' and 'Supernova'.
UNIT - or some other secret governmental agency more closely linked to the United States - probably had to do the same thing for Alexander Scott and Kelly Robinson. Since Lucas Hilton reminisced about the TV show, 'I Spy' was probably made in order for the exploits of the spies to be debunked as just being part of the TV series. 'The Middleman' used the names of Alexander Scott and Kelly Robinson as aliases for himself and his sidekick "Dubby". But in his case, he probably knew about the two spies from his agency's files.