Didn't it occur to Chitanda (or anyone) that those chocolates contained whiskey? Really? Speaking of Chitanda, what did she contribute to the team anyway, other than saying that Theory A or Theory B don't feel right? Everyone there was trying to deduce the logic behind the theories, and Chitanda did anything but that.
Let's see how the mystery is solved in the next episode, and see what detail did everyone apparently missed.
Well, that's why Chitanda is "curious" for Oreki. She doesn't behave normally like the uptight princess type. (Good grade, rich family, pretty, etc.)
But come on AC, you of all people should have figured out the hierarchy by now. Chitanda doesn't do any interpretation. The only time she ever did it was during the main story line of Hyouka. And even that, it was more of an introduction than actually a theory. Chitanda fulfilled her role. She is the club president and the person who introduces the mystery. That's all she's there for. She is the initiator. Anything else and she'll be out of character.
Mayaka and her attitude is the investigator of the group. Ask the important questions, compile the introduction.
Satoshi is the database. Collects the data and orders them.
Oreki is the resolution. He puts everything together and solve it.
This is how the series going to be laid out from beginning to finish.
Now as for this arc's mystery itself. Who here has an explanation? I think they are "testing" Oreki. At least that's how I felt with all three stories focused on Oreki at some point. I don't know.
But the last story is somewhat plausible. However, not by an outside source. I think there are two possibilities:
A) It was an accident. The victim got his arm chopped off unexpectedly and fainted. Or else, wouldn't there be some sort of scream? Wouldn't the other have heard him? I don't see any sign of struggle in the room either. I kind think we should look up. Maybe the victim fell from the floor above or something. I mean why would he lock himself in the room? The door was locked, right?
B) The three left behind killed him. I am aware that they didn't have the key but this might have been planned by the three of them. If this indeed was a crime, then there had to be more than one suspect to subdue the victim without any sound made.