When Andy is getting his Elvis Presley impersonation together he puts on a guitar, but in the next cut when he's facing the audience the guitar is gone.
When Tony Clifton walks onto the set of Taxi (1978) with 2 prostitutes, the blonde is wearing a light purple top but later when sitting on top of the prop cab she is wearing an orange top.
After Andy gives his Elvis Presley impersonation, the same guy (long hair in a pony-tail) can be seen rising from his seat several different times to give a standing ovation.
Jim Ross was not the ringside announcer during the Jerry Lawler vs Andy Kaufman match in Memphis. Lance Russell was the ring announcer and ringside announcer.
At the end, the MPAA certificate number is listed as 369,916, which has one digit too many. At the time it should have been near 37,000.
Numerous anachronisms can be chalked up to artistic decisions;
the film intentionally plays fast and loose with the timeline. For example, the Carnegie Hall performance was years before Andy Kaufman's cancer diagnosis; the title song wasn't written until after Andy's death; Andy didn't meet Lynne Margulies at a wrestling match; Stacy Carter hadn't met Jerry Lawler before Andy died (and certainly hadn't married him). Andy performs his imitation of President Jimmy Carter (elected 1976) before Saturday Night Live (1975) begins.
Andy is playing a Ms. Pac-Man (1982) arcade machine, when George tells him that the producers of Taxi (1978) agreed to his terms. That's three years before the game came out.
Lorne Michaels plays the executive producer of Saturday Night Live (1975) in 1982, when the infamous vote to ban Andy Kaufman took place. In reality, Dick Ebersol was executive producer of the show; Michaels left the show in 1980 and did not return until 1985. The vote was presented by then cast member Gary Kroeger.
Well before his Saturday Night Live (1975) begins, Andy is seen doing his classic impression of "Mr. Carter, the president." Jimmy Carter was not yet even running for president at the time, and didn't get the office until halfway through the program's second season.
There is an African American Rockette at Carnegie Hall. The Radio City Rockettes never had an African American member until 1988.
A banner says that the Andy Kaufman-Jerry Lawler match is taking place at a Global Wrestling Federation event. The match was held in 1982 at a Continental Wrestling Association event in Memphis, TN. The Global Wrestling Federation was a Dallas, TX promotion that existed from 1991-1994.
George presents an offer to star in Taxi (1978), and Andy replies that "ABC will just have to accept" his conditions. George hadn't mentioned ABC, so how did Andy know which network was involved?
During his 1979 Carnegie Hall show ("Milk and cookies for everyone!") Andy presents an old movie clip and says, "We have with us the last surviving cowgirl from that 1931 film." However, the clip shown is from a 1942 movie, The Forest Rangers (1942).