The Mad, Mad, Tea Party Affair - S1-E18
Revealing mistake: When Riley is trying to escape after being exposed as the saboteur, he shoots a pair of U.N.C.L.E. agents. On the right side of the screen, spent shell casings are very obviously thrown into the shot from off screen. (00:43:40)
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 ★