Razafi's facial hair alternates between stubble and a full beard throughout the story. This is especially evident in the scene where Steed captures him and takes him to the Colonel's house.
Mrs. Peel says the tsetse fly is Glossida trypanosoma. Actually it is genus Glossina; species morsitans, or fusca, or papalis. All three species cary the sleeping sickness parasite, Trypanosoma brucei.
Obvious stunt double for Steed during climactic fight in the jungle.
The croaking of frogs heard in various scenes belongs to the North American leopard frog which is not native to Africa or the UK.
When Professor Swain is performing rituals over Kendrick and Mrs. Peel is standing behind him, the curtain behind her right shoulder partially pulls back for no reason.
When Steed awakens in the morning at the Colonel's residence, he is cleanly shaved and looks as fresh as a daisy.