Continuity mistake: When Jane speaks to the owners of the restaurant, the female owner is writing something and also has a drink. She takes the drink with the pen in the same hand. When the shots changes, the pen is no longer in her hand. The shot goes back to the original position and the pen appears again.
Continuity mistake: In the beginning when Patrick is talking to the widow Erica Flynn at the police station, when she first leaves the interrogation room the zipper in the back of her dress is down about four inches. As she is walking to the elevator, when she goes into the elevator and turns, you see that it is now zipped up completely.
Continuity mistake: This happens right at the very end at the hotel room in Mexico. Jane and Lisbon are sitting on the bed and the cellphone rings. It's Red John calling. There's a beer bottle next to the phone on a round table. At first the label faces towards the middle of the table. When Jane picks the phone up, the label now faces the other way.