Visible crew/equipment: After Dr. Samuels comes down the stairs and starts to talk to Charlie, a shadow of a boom mic can be see behind Charlie.
Charliegate - S1-E3
Continuity mistake: Dennis writes "who cares" on the chalkboard. The placement of the letters changes, most noticeably the S.
Question: Did they ever show Mr. Moore teaching another class? Surely he had more than one class a day.