Audio problem: When Peter walks into the washing room Elizabeth says "hello Peter" but her lips do not move.
Continuity mistake: Yoshi and Mark are in the room with ballroom-dancing patient. Yoshi is writing on the chart - when the shot changes the paper on the chart is tented up, with no time for it to change position. When the shot changes again, he has the chart down on the instrument tray, again with no time for the change.
Answer: It was in "Chaos Theory", the first episode of season 9 (time code 00:13:55).
Super Grover ★