In one scene Poroit is standing next to the tree where the wasp nest is and there are no wasps, then in the next scene the wasps are back wasp buzzing around.the tree with the nest.
Poroit says he substituted washing soda for the Potassium Cyanide. However washing soda is Sodium Carbonate which is powdery while Potassium Cyanide is crystalline like table salt. They show a crystalline compound being added to the tea which could not be washing soda. In addition, it is immediately obvious that the washing soda is not the crystalline Potassium Cyanide.