Black Butterfly Murder Case: File 1 - S3-E1
Stupidity: Since "Touno" was prominently featured on the photo of a lengthy article about the butterfly crypto-entomologist Shimon Madarame, it's quite strange to say the least that Kindaichi and his journalist friend wouldn't have the slightest clue about his name or generic occupation. Generally a magazine does not put a person in 1/3 of a double page spread without at least hinting the reader about a person's identity, especially when they are not doing anything in the picture.
Stupidity: The master goes through all the trouble of making Luke the vessel so Luke can go and kill several people and risk getting the attention of the slayer, when all he had to do is have his minions go out and kidnap a bunch of people and bring them to him and he could've fed off them himself.
Stupidity: Some ancient advanced civilization took to the task of building this amazing net of stargates that enables instantaneous traveling over hundreds of light years or more, but any stargate can be disabled by anybody just by covering it with dirt or rocks. Apparently if the stargate is buried then it becomes inactive. See Season 1 EP.1.
Suggested correction: This is just you having a different opinion on how the Stargates should work. In fact, the ability to make a Stargate inactive by burying it is a brilliant move by the Ancients. Burying the gate, or even creating a barrier, prevents enemies (like the Goa'uld) from having a convenient way of invading a planet. Although some races, like The Nox, show the ability to activate a Stargate without having to form an unstable vortex.