Pam states that there are no staff birthdays coming up in the next month: Meredith's is the next one, and it's still a month away. Later in the series, in episode 7 of season 4 (Survivor Man), Angela lists the birthdays that month, in order: Kelly, Creed, Oscar, and Meredith.
At the 6:43 minute mark over Michael's head, you see Angela making copies. She is in a cream sweater as she is in the rest of the episode. However, at around 7:20 minutes she is seen wearing a black sweater with a white shirt for one cut scene. It isn't as noticeable, but you can also notice Oscar is wearing a different shirt at that 7:20 second scene. The one at the 7-minute mark has the same pattern, but a different base color.
In the end of the episode, when Roy catch Jim "flirting" with Pam, Jim reveals that they was just messing around with Dwight. At that point, Dwight had not yet dyed his hair. Next scene, Dwight has dyed his hair blond, although knowing they were pranking him- although this might not be a goof. It might have been intentional the comedic irony. Here, Dwight was so convinced that he had the upper hand and foiled Jim's plot, but, it's possible he either maintained belief that a small part of Jim's scheme was true and it wasn't all a farce; or he had a brief moment of poor memory /stupidity, and had it in his mind he should still dye his hair somewhat out of absurd forgetfulness . The scene at end would not have been funny if his hair was revealed to be blonde earlier.
When Jim and Dwight are in the warehouse, about to hide Dwight in a box, the close ups show him in a small square box, while the long shots show him in a larger rectangular box.
One of the employee's car's license plates is 8326-FLO. In Pennsylvania, standard plates are three letters, then four numbers (ex. AAA-1234).
In The Office season 1 DVD, the synopsis for "The Alliance" claims that Dwight wants "John" to join the alliance. Dwight and Jim form the Alliance - John is the real name of the actor who plays Jim.
Meredith was called an accountant in this episode, however she's a Supplier Relations Rep.