Evil Spirit of the Diving Pool - S1-E18
Other mistake: In this episode, we learn that Kindaichi can't swim. However, the series is a continuation of the first one from 1997: in a few instances (the Ghost Passenger Ship Murder Case, The Kidnapping of Reika Hayami Murder Case, with Reika appearing as a key character here) Kindaichi could swim just fine and in fact would bravely dive in the ocean to save someone and swim downstream in a mountain river when gravely injured, respectively.
Other mistake: In this episode, Hera's ears are shown for the first time thanks to her civilian disguise. As for all Twi'lek women, they're shaped like cones. However, they are too large to fit under the ear coverings of the pilot's cap she usually wears, when they've been shown on the few occasions she hasn't been wearing goggles or a pilot's visor.