When Barnaby and Jones drive to the airfield to look at the second body, the car arrives in heavy rain; there are puddles on the ground and distant rumbles of thunder can be heard. But when they get out of the car a few seconds later, the ground is dry and people in the distance are casting shadows, showing that the weather has suddenly become sunny.
When the exhaust gas is first seen in the car, it is coming from the dashboard (front) of the car, yet the hose from the tailpipe was in the rear side window.
When they 1st look at the boys body in the car (the 1st murder), his eyes are fluttering. Seems to be a common error on this show.
The Canadian flag (the red maple leaf) shown in the dance hall was not adopted until 1965. Prior to that, the flag was the Red Ensign.
The Union Flags hung in the hall, on the walls, and from the beams (during the dancing to "Goodnight Sweetheart") are hung upside-down.
The American flag hanging in the dance hall is a 50-star modern flag and not a WWII-era flag.