Starring: Tim Matheson, Don Messick, Danny Bravo, Mike Road
Attack of the Tree People - S1-E19
Other mistake: The captain of the ship that picks up Race and Dr. Quest talks with a German (and sometimes French) accent but the commands he gives are in Dutch, like "Volle kracht vooruit" and "Pik de drenkelingen op" (the Dutch accent is very different from the German accent, as is Dutch from German).
The House of Seven Gargoyles - S1-E23
Jonny Quest: We have a proverb in my country, Hadji - seeing is believing.
Hadji: We have one in mine, too - I'm from Missouri.
Trivia: "Calcutta Adventure" is the episode where Hadji and Jonny meet and become friends after Hadji saves Dr. Quest's life from an assassination attempt.