Factual error: Ole and all the Thrush baddies call the missing chemical component a "catalyzer," repeating the term throughout the episode. This was a scriptwriter's error, which only David McCallum, to his credit, corrected: he had Illya say "catalyst," which is what the writer meant. "Catalyzer" isn't a word. (00:10:45)
Continuity mistake: The Thrush assassins have an armed golf cart (with a machine gun that handily spews both flames and bullets at the same time). When the cart overturns, the two men fall into a sand trap and tumble several feet away from the vehicle. In the very next shot, they're lying right beside the cart again. (00:02:40)
Other mistake: Illya orders an espresso from Fred, the coffee house proprietor, but never pays for it. And Fred doesn't take a bill to his table or speak up when he leaves without paying. (00:10:00)
Continuity mistake: Sylvia is carrying her huge "opus" sculpture out of the art gallery. In the next cut, though, we see a full shot of her showing both her hands empty: she's not holding the sculpture. Next shot, she has it back in her hands again. (00:24:25)
Answer: He must have ridden in an Eaton's store elevator while he was in Canada at some point. For some reason, this elevator reminds him of it. The show's original concept had Solo being a Canadian, so this may be a minor nod to that fact.
raywest ★