Robert Aldrich is seen directing "Sodom And Gomorrah" on a Hollywood soundstage, but the film was actually made entirely in Italy and Morocco.
The establishing shot of Crawford arriving at Davis's play, "The Night of the Iguana", shows the Palace Theatre on the marquee. "Night of the Iguana" played the Royale Theatre (which has since been renamed the Jacobs).
When Bette and Joan go to Hedda's house for dinner, Hedda says that the Fondas are coming to dinner on Wednesday. Henry Fonda was unmarried between 1961 and 1965.
The 1958 Chevrolet Impala convertible shows a front California license plate with a registration sticker on it. In 1962, as now, California plates do not display a registration sticker on the front plate, only the rear.
On the set of "Whatever Happened To Baby Jane?", the reflection on Bette and Bob's glasses are blue, as if from a computer monitor. There isn't anything visible on set that would cause this type of reflection.
The telephones were modular, which was not introduced until the 1970's.
At the lunch with Hedda Hopper, the song "Wives and Lovers" sung by Jack Jones plays. This lunch occurs during the filming of "Whatever Happened to Baby Jane", filmed in early 1962, but the song was recorded in 1963. Perhaps the song they wanted to play here was "Hey! Little Girl" by Del Shannon, released in early 1962 (the lyrics of "Wives and Lovers" start with "Hey, little girl....").
When Bette and Joan arrive at Hedda Hopper's home for dinner, Jack Jones' recording of "Wives And Lovers" is playing in the background. That record was released in 1963. The scene takes place in 1962.
During the 1955 Dinner party, Truman tells Paley to tell his boys at 60 Minutes about the Woodward story. 60 Minutes did not debut until 1968.