Revealing mistake: Diamond's office building has an automated push-button elevator (quite a rarity in the 1950s). But when he and Hastings exit and walk into the hall, the elevator doors remain open long after they should have closed. There's also no break in the floor where the steel plating for the lift car ought to be, making it all the more obvious that it's a studio mock-up rather than a real elevator. (00:01:20)
Richard Diamond, Private Detective (1957)
1 revealing mistake in Another Man's Poison
Starring: David Janssen
Visible crew/equipment: Diamond parks outside the apartment house, and when he opens the car door, it mirrors several stage lights and reflectors.