Continuity mistake: The date of Helen Kimble's murder is given here as Sept. 19, 1961. Previous episodes, however, had established it as occurring on Sept. 17, 1960.
Continuity mistake: When the lab equipment shorts out after the earthquake, the unconscious Major Brothers is lying with his head propped up against the wall. But when Hamilton reaches him in the next shot, he's suddenly lying flat and is nowhere near the wall. (00:21:45)