Continuity mistake: During McCoy's struggle with the orderly, only half of the plastic colored bottles strewn on the table are knocked off onto the floor. But when Nurse Chapel hurries over to tranquilize the orderly, the rest of the bottles vanish, leaving the table completely clear. (00:19:10)
Continuity mistake: When Kirk, Bones, Chekov, and Spock go over to the Defiant, the suits they have on have a black support bar in the left side of the headpiece. When the camera looks down at the dead men and back to Kirk, you see the bar is on the right, and his hair is parted on the right. The very next look at Kirk, the bar and the part of his hair is back on the left.