Jim added only 3 keys to Dwight's key-chain, yet Dwight removed 5.
While in the elevator with Pam, Dwight establishes a "pee corner" on the side behind the button panel. In the next elevator scene when Hank is fixing the elevator, Pam tells Jim that there is pee on the floor, but you can clearly see that the "pee corner" is dry.
Pam's hair clip- in the first part of the episode her hair clip is all black with flowers or something like that but then after she and Dwight get in the elevator she has a totally different more plain brown hair clip in.
When Michael writes "Don't with a slash through it, the lettering changes from shot to shot.