In episode 2, Hashiba plants a phone in the classroom under instruction from Kobayashi, and then has Ms. Hanabishi show it to the class, asking who it belongs to. Hashiba replies that it belonged to their murdered teacher.
Somehow, from this sequence of events, Hashiba is able to deduce that the teacher-killer is in their class, as he reports to Kobayashi when he blusters his way into the interrogation room later.
I don't follow Hashiba's logic here. We did get those shots of an eye darting around (nervously?) during the sequence, but I'm not sure what to make of them. It can't be that Hashiba noticed Hoshino (the killer) acting suspiciously, since if he had, he could have just told Kobayashi about her right away. But nobody besides Hanabishi and Hashiba himself said or did anything (besides the darting eyes) during the staged phone-finding... so on what grounds was Hashiba able to conclude that the killer was in the class?
