The Alchemy Murder Case File 4 - S1-E9
Continuity mistake: In the flashback when we see the culprit holding the newspaper with the news about the suicide, their thumb is on the blue box, which is at the edge of the page. Then they fall on their knees crying, and there's suddenly an extra bit of newspaper to the right of the box and their hand is on that. (00:15:15)
The Alchemy Murder Case File 4 - S1-E9
Plot hole: The ending is funny, but it does not make sense, since as it was mentioned in the first episode, there was literally 1 ton of metal to remove, and it was in the shape of a door. Not only it would have needed 32 trips (as the nerd girl says in the first episode) from the secluded house to a large boat they somehow needed to have standing by and was undetected when the island was searched earlier, but they also needed to dismantle the door, since that's what the gold was turned into.