When Hildy gives Kelly the old Air Force photo of her nephew, there are numerous black marks on the back. In the following scene, when Sabrina is looking at it, the back is clean white.
When Sabrina finds Doug on the floor and helps him to the bed, her hands are empty. A moment later, she's holding a cloth in her left hand.
Doug O'Neal uses a credit card to open the cabin door. The door knob is on the right side of the door. The door would open to the left. When Doug opens the door and steps inside, the door knob is on the right hand side and the door swings open to the right.
In the episode prior to this one - Circus of Terror (1977) - when asked if he is married, Bosley replies, "Not lately." In this episode's first scene at the Townsend Agency (and only in this scene), David Doyle is wearing a wedding ring.
While Kris and Kelly are on horseback chasing Lon Molton, all close-up shots of Kris are flipped: the writing on Kris' shirt is backwards. In the final close-up at the end of the chase, the writing appears correctly.
In the old Air Force photo of Frank and Doug, the actors' faces are quite obviously pasted onto the original picture. Doug's face and neck are pasted in but only Frank's face, making his more noticeable.
Before Frank turns off cabin light, light switch is clearly already in the off position. After he shuts off lights, switch is still in the off position.