A New Day in the Old Town - S2-E1
Other mistake: The killer from another dimension shape shifts into the appearance of the victim, leaving the victim's body. But it transforms into Charlie's appearance and leaves behind its former female nurse shape, hiding Charlie's body to dispose of later. It would have needed to transform from the nurse shape, not out of nothing. The original nurse's body was not at that location.
Suggested correction: The shapeshifter transformed into Charlie using his dead body which it then disposes of at the end of the episode.
But when the shapeshifter transforms into Charlie, he shouldn't be leaving the body of the nurse behind since he had killed the nurse before entering the hospital and transformed there into her. The only dead body in that last scene should be Charlie's.
Other mistake: Carrie the assistant brings Lisbon and Jane to Stutzer's office. She swipes her card to open the door. However, she does this upside down, swiping the bar-code instead of the black magnetic strip, on which she is holding. (00:09:30)
Other mistake: Season 2, Episode 20: "To the Lighthouse" - In the flashbacks to the jungle, John is considerably younger. Sarah however, is not. Adults don't change nearly as much as a child would in the same time period, but this is a pretty big jump back in time. John is only a child in the flashbacks, putting Sarah in her mid to late 20s. Yet she still looks 35 and even has the exact same skin and facial structure.