[ He raises his brows at her frankness, and seeming lack of judgment. He pauses, locking eyes with her, debating whether or not to tell the truth. But this time, he does, in fact. ]

...My teacher thought I was trying to skip class when I took too long with the bathroom pass and accidentally missed the whole class. When I came back, she didn't believe me when I told her I got lost. And locked in a basement.

[ This sounds like a case of a teacher being unreasonable, until he continues, tagging on that final detail far too plainly. What. ]