At about the 2 hour point, Rena and studio stooge, David, are talking in her house. As the camera angles change, the background set switches between a bookcase and a railing behind them while the scene remains the same.
When Jonas and Monica are touring the house, they walk into the master bedroom and she says, "adult playroom". Then the walk into the guest room supposedly, but you can tell it is the same door from a different angle, as the three thermostats are on the same side.
The story takes place in the 1920s and 1930s, but Carroll Baker's, Martha Hyer's and Elizabeth Ashley's hair styles are strictly 1963 from start to finish.
As Dan and Rina Marlowe drive from the train station, circa 1927, there are a couple of 1940s cars parked in driveways in the background.
The slide rule that Jonas holds after talking with Buzz and Phil (Morrissey) at the aircraft factory is of 1960's plastic construction; a slide rule of the period would be made of wood, visible as such at the ends.
When Rina is on the chandelier, it is never explained how she got there: the chandelier is too high off the ground for her to be manually lifted up and there is no visible means of access.