Continuity mistake: When Meredith's hair catches fire, we never see her face (as it's a stunt double). After Dwight uses The Fire extinguisher on her, the shot cuts (although she is still in the frame) and her hair is different, as it is now the original actor that plays Meredith. (00:05:50)
Continuity mistake: Michael's scarf is above his collar in the first shot, but moments later, seemingly without moving, his scarf is tucked below his collar. (00:06:40)
Plot hole: When Andy duels Dwight, it doesn't make much sense for the office employees to not be outside watching The Duel. On other occasions, like Pam hitting Michael, they did watch outside. To not have any one of the office workers watch or even supervise the situation, including Jim, who acts concerned throughout the unfolding ordeal, is unlikely. The reason everyone stays in is so Andy's plan of blindsiding Dwight with his car can work out.
Lecture Circuit: Part 2 - S5-E15
Continuity mistake: When Jim and Dwight are talking about the activities for Kelly's party, Dwight is attempting (horribly) to blow up a silver balloon. Just after Jim finishes reading The List of proposed activities, Dwight says, "You're right, forget horse hunting, it's stupid." Immediately after he says this, the shot changes and he is now holding a brown balloon. (00:16:30)
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)
Continuity mistake: When Kevin is writing Pam a check, he flips it open so the check register is folded under the checks. After he says "wait till Monday", the check register is no longer folded under the checks.
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)
Continuity mistake: When Dwight is talking to the kids, he picks up one fry. In the shot of him from behind, he's holding two fries. It goes back to one fry when he takes a bite.
Plot hole: When Jim's bank calls his office, Kevin is there and ends up pretending to be Jim. The Banker automatically assumes that he is not in Puerto Rico only from asking his address and social security number. It would have been very plausible for him to have forwarded the number to his cell phone, where the same scenario could conceivably occur (since The Banker refused to listen when Kevin tried to correct her).
Continuity mistake: When Jim is outside comforting Pam after she finds out her mother is dating Michael, he begins to explain a mallard recording device that Dwight gave to him and used a big hand motion that put his hand in the air. In the next shot, the hand that was in the air is now gripping his coffee cup.
Double Date - S6-E8
Continuity mistake: In Fun Run (4-1) when Michael hits Meredith in the parking lot, it is said by him that it was on company property, but in this episode Pam says that the hit in the parking lot will be off company property.
Continuity mistake: When Michael begins the conversation with Jo, the door behind him is closed. After a few lines, the door is open. (00:19:10)
The Manager and the Salesman - S6-E15
Continuity mistake: When Michael enters the room he messes with Jim's hair and Jim's hair is noticeably different, however a few different camera angles later Jim's hair is back to normal even though he couldn't have possibly had time to touch it. (00:09:10 - 00:09:50)
Continuity mistake: When Jim and Michael are in the conference room with Jo, Michael messes up Jim's hair. A few shots of Jim later, his hair is nicely combed again.
Continuity mistake: When Jim reveals the tiny desk underneath his "Quad-Desk" to Dwight, Dwight sets his briefcase down on a chair not shown in any previous shot. (00:21:05)
Happy Hour - S6-E20
Continuity mistake: When Michael is doing press-ups Angela is sat, then she stands to see what's going on - away from her chair, it cuts to another shot, and she is sat down again.
Continuity mistake: Andy states that he has a step-mother who is/was a secretary, but in all other references to Andy's father's wife she is Andy's biological mother.
Character mistake: Carol says that Michael proposed to her on their fourth date. The proposal happened in Season 3, Episode 6, Diwali, and in that episode, Carol mentioned that it was their ninth date.
Continuity mistake: In this episode Michael can't ride a bike. But in episode 3-10, Michael was seen riding a bike with no problems.
Character mistake: In the scene where Ryan and Andy are taking a tour of Gabe's bedroom, Ryan says "Hey, Marantz tube stereo from the 1970s" It is in fact a Marantz SR 1000 stereo receiver. This model uses solid state electronics, not vacuum tubes. (00:13:30)
Answer: In the 2007 episode "Ben Franklin" when Jim is talking to Pam there is a candy bar with a purple wrapper that says "Picar-" I assume picaroon, it's hard to see past Pam. I found this trying to investigate what that candy bar is lol.