Suzanne mentions to John and Joyce during a Three's Company rehearsal that she had her 11-year-old son when she was 17. That would make her (at the time) 28. However Suzanne was born in 1946 which meant the year would be 1974 or 1975. Three's Company didn't start until 1977 so she couldn't be saying this to John & Joyce.
EDITOR'S NOTE: As listed in the end credits, and because Three's Company was an ABC show and this was an NBC movie, there are many errors regarding the show and how they are presented in this telefilm because telling the story EXACTLY how it happened would most likely result in legal problems between NBC and ABC (as far as the episode tapings shown) and the Chris Mann issue with his "Come and Knock on Our Door" book.
Early in the movie, right after Three's Company is a hit, there is a short music montage which features a clip of Joyce DeWitt filming a Leggs commercial. She did not endorse this product until much later.
Fred Silverman's VARIETY title is in red, and the producers is in green. Then, in another shot, the producers newspaper has a red title, but isn't Variety.
Don Knotts says he never dressed in Mr. Furley's crazy clothing style. But, when he shows up to discuss joining the cast he is wearing an outfit like Ralph Furley would wear.
Three's Company films on Fridays. However, the producers and John hold the audition for Jack's fiancee on a Friday. Joyce says she comes in the day before filming to set up her dressing room, which would mean the show tapes on Saturdays. Also, the woman casted would never become Jack's fiancee. She would only become his live-in girlfriend which gave the spinoff its plot (that the two weren't married).
After Suzanne films her first "Chrissy-tag-scene", the security guard purposely brings her by the girls audtioning for Cindy Snow. However, the first Chrissy tag scene appeared the week before Cindy's first episode. The producers should have casted her by now, and why would they be casting on a taping day?
The same audience shots are reused throughout the film at tapings of different episodes.
Ted says "ABC wants to spinoff The Ropers". However, he should have said "ABC wants to do a spinoff with The Ropers", as The Ropers would be a spinoff of Three's Company.
During the first season wrap party, everyone knows of how the show is such a big hit. However, the season would have already been completed as all six first-season episodes were filmed before the first episode premiered.
The episode Suzanne first missed the taping of was "A Crowded Romance", an episode that Don Knotts did not appear on. However, Ted briefly talks to Don Knotts, fully costumed backstage just a few minutes before filming was supposed to start.
Many cast members hair styles changed throughout the series (especially Joyce DeWitt's) but none of the re-enactment actors change styles.
After the producers proposed the spinoff to Audra Lindley and Norman Fell, it actually took Norman Fell at least six months to sign on, but in the movie he agrees in less than two minutes.
After it is revealed that Fred Silverman has left NBC, we see the new president's name displayed on the door. But, in the next shot, you can see that Fred Silverman's nametag has reappeared on the door.
The apartment door is the normal curve shape in one shot, but is a normal square door in all of the other scenes of the movie.
The "Three's A Crowd" spinoff was not developed until after season eight began and the ratings started to fall. In the film, John Ritter was proposed the idea right after season 7 ended.
Even though Terri was on the show longer than Cindy, the actress portraying Cindy has more lines than the actress playing Terri (who has no lines).
After Suzanne Somers is casted, it seems like the three actors are meeting for the first time on the night of the taping when they should have spent a week of rehearsals together.
After the missed tapings, we see the actors receiving a blue and a pink copy, one if Suzanne shows up and one if she doesn't. When she comes in the room, Suzanne receives both copies as well. She should have only been given the copy with her in it, not both of them.
The "Three's Company" name was not thought of until the original pilot was made. The producers use this name while pitching the show to the networks, a long time before the pilot was greenlit.