When Barnaby and Jones watch historic documentary movie, Barnaby says "this is interesting, Spitfires over Morton Fendle". However, it can be clearly seen that the aircraft shown on screen is the Hawker Hurricane, not Supermarine Spitfire.
The Murder Victims:
1. Simon Bright- carbon monoxide poisoning
2. Laura Sharpe- bludgeoned
3. Tony Kirby- stabbed
Goof: 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.