David Letterman's CBS set is used when he is supposedly at NBC (because NBC refused permission to use that set).
When Mandy is handing her panties over to Jackie, he is shown taking them from her hand and putting them on a hanger. In the next shot Jackie picks them up off the table and puts them on the hanger.
The reflection of Howard talking to Kenny on a lamp when no sound is heard.
The position of Moti's newspaper on the desk at Howard's WRNW interview.
Howard's headphones reappear on his head as he tries to restart the turntable after knocking the cartridges onto it.
Robin makes the statement that Howard, "...wasn't old enough to be in Vietnam" and Howard replies, "no duh". The Vietnam War started in 1965 and ended in 1975. Howard was 18 years of age in 1972 which does make him old enough to be in the war.
Howard is attempting to give a woman an orgasm over the phone. He is speaking to her on the phone and at the same time she is listening to the show on the radio. There is a time delay of several seconds before the show is broadcast over the air. Being on the phone and listening at the same time would create feedback and would not allow the conversation to continue as portrayed.
Howard Stern did not have long hair when arriving at WNBC, and in fact did not grow it long until approximately the time he was hired by WXRK.
The day Robin was fired from NBC was a warm sunny day, the next day Ross, Robin's replacement announced the anniversary of John Lennon's death. Lennon died on 8 December 1980.
Howard was not that thin and his hair was not that long during his WNBC days.
When Howard and Allison pull into the gas station and he discusses the fact that he often holds back what he is really thinking while on the air, you can clearly see the car's rear-view mirror folded upwards and out of the way in order to avoid blocking the faces during the conversation.
After Howard is joking about Alison's miscarriage on the air, before Fred jokingly plays TAPS, Howard comments "very sad music", before anything even starts playing.
Robin's replacement reads a story about the second anniversary of John Lennon's death. Later, after he leaves, Howard reads a story about the death of Princess Grace. She died in September of 1982 while the second anniversary of Lennon's death was in December of '82.
In the scene when Howard Stern is reading from a book in the studio, you can clearly see that lines from the script are glued into the page that he is reading.
The billboard logos of Budweiser and Miller Beer are the present (1997) logo and not the correct logos of the time.
When Howard is backstage at the 1992 MTV Music Awards, John Popper of Blues Traveler is seen playing his harmonica in the background. Although the band formed in 1987, Blues Traveler was virtually unknown until their breakout album "Four", which was released in 1994. Popper would certainly not have been backstage at the 1992 MTV Music Awards.
When entering the Detroit radio station in 1980, a poster of Tommy Shaw's "Girls With Guns" album is on the wall. In 1980, Shaw was still a member of STYX and wouldn't release his "Girls With Guns" album until 1984.
As Howard's car is seen driving over a bridge, on his way to New York for his new job at WNBC, David Bowie's "Let's Dance" is playing. Howard's first official day at WNBC was September 6, 1982, so obviously he had to arrive in New York around that date. However, "Let's Dance" was not released until March 17, 1983.
AC/DC appears in a scene set in 1985, but Phil Rudd is seen as their drummer. In 1985, Simon Wright would have been their drummer, as this was during the decade or so that Rudd was on hiatus from the group.
When Howard is interviewing the first naked lady in his NBC Studio, and goes over to the spot where he is about to lie down on the floor, Gary Dell'Abate can be seen watching from the Engineer's Booth. When the camera angle changes, Gary is no longer in the shot. This time period was way before Gary was a part from the Howard Stern Show.
While Howard is in Washington DC, he helps a woman have an orgasm over the air. When this happens, the scene shows a car with New York plates jump the curb at an intersection along E 189th St in the Bronx. The radio station in Washington DC was local and not syndicated so somebody in New York couldn't be listening.
Early on in the film, Howard says that he is heading to New York from California, but the scene where he gets ready to check in and board the plane takes place at Newark Liberty International Airport.