Character mistake: When it briefly shows the sign for their wedding rehearsal dinner, they spell Jim's last name wrong. The sign reads "Beesly-Halpret" wedding rehearsal dinner, not Halpert. (00:11:00)
The Meeting - S6-E2
Character mistake: When Dwight and Toby drive by Darryl's house to investigate his injury, a New York Yankees sign is on the front porch of Darryl's home. Throughout the show, however, it is strongly implied that Darryl is a Philadelphia Phillies fan. This is a character contradiction. (00:10:19)
Suggested correction: Michael didn't establish the contract with Hammer-mill. Rather, he locked them up as an exclusive supplier. It's unknown if they were already selling the products to Dunder Mifflin alongside Staples and Office Max.
Wrong, Josh says they cannot sell Hammer-mill products as they are exclusive to Staples so therefore they wouldn't have been able to sell there products alongside as mentioned before until Michael made them an exclusive to them solely, Dunder Mifflin. Therefore the original mistake stands true.