How Green Was My Thumb? - S3-E17
Continuity mistake: When Johnny and Roy visit Mrs. Johnson on the 6th floor, they take the elevator near the nurses' station, at the south end of the ER wing, and when they exit the elevator they turn left to room 603. This is completely impossible considering the actual floor plan of the hospital, since in all the exterior shots of the ER it is only 2-storeys.