Factual error: When Columbo initially latches onto the radio dilemma (which ultimately solves the case) the dial is tuned all the way to the left. He later tells someone that the radio is set to 'Classical 52', but an AM radio starts at 54, meaning 540KHz. There is no 52.
Factual error: Probably an in joke - the wheels of the "airliner" shown landing at LA international airport are those of a B52 bomber. They are very distinctive and look nothing like those on any airliner ever made.
Trivia: Peter Falk's real-life wife appeared in 6 episodes, each time as a different character.
Question: The examiner says he can't tell which blow hit the victim first. Columbo says he's lying on his back and says the blow to the forehead was first. Why did he think that? If the first blow hit him on the forehead and he fell on his back, how did he get the second blow on the back of his head while he was lying that way?
Answer: Columbo deduces that the first blow must have been to the front of the head, the force causing the victim to fall backwards and hitting the back of his head hard on the ground.
raywest ★