This is Henry Darrow's favorite "Harry O" episode.
This episode contains substantial recycled and repurposed footage from the first of two "Harry O" pilot films -- "Such Dust as Dreams Are Made On (1973)." This pilot was broadcast in March 1973, a year and a half before this episode This explains, among other inconsistencies, Lt. Trench disappearing and Mel Stewart's Sgt. Granger appearing in a pivotal scene. Since the original pilot's paint factory scene prominently featured Martin Sheen, it was cut, thus requiring a new explanation for Harry's eye injury.