Linda Thorson had been asked by the producers to bleach her hair blond and it devastated her hair forcing her to wear wigs. The final scene in this episode is the first time we see Linda Thorson's real hair.
About 4 minutes in the helicopter seen is a 1965 Hughes 300 (model 269B) serial number 450189 (registration G-AVZC). It crashed and was damaged beyond repair on March 28, 1990. It was also seen several weeks earlier in the "Super Secret Cypher Snatch".
On Julian Glovers's fourth appearances, this was the only one where he played a character who was a protagonist.