Hida Mechanical Mansion Murder Case: File 3 - S1-E20
Plot hole: The plot is based on the fact that a certain character was disguised as the presumed first victim. At the same time, the two characters have a different body type (otherwise the gap in the window would be obviously too small), so the turn of events does not make sense. Moreover, supposedly the victim suffered serious burns in a fire, which would be absent in the corpse.
Hida Mechanical Mansion Murder Case: File 3 - S1-E20
Plot hole: Even considering the fact that the corridor was dimly lit (but not in complete darkness), it is impossible to plan the 'switch' the way it happened. For the plan to work, the killer needed to go through a revolving door at the same time as Kindaichi; there was no guarantee which of the two halves of the door he'd make spin, though, and he needed precise timing (against someone running through the door at full speed) and not make a sound with the keys he was carrying. The corridor (and therefore the door) is also so narrow that you wouldn't be able to ever pull it off.
