Revealing mistake: The money that Micah dumps out of his backpack is very obviously fake. In fact, the $20 bills have Benjamin Franklin's portrait on them.
Visible crew/equipment: When Claire runs away from Bob after he calls her "Ms. Bennet", you can see Bob's shadow and another person's shadow on the ground. Since no one else was standing next to them, it has to be a crew member, most likely a camera man based on the odd shape of the shadow.
Continuity mistake: After throwing the laptop, when Mohinder takes the key out of the book, the tape is bunched up and stuck to the key, but in the next shot the tape is fresh and sticking out freely.
Continuity mistake: When Maya is arrested, she starts manifesting her powers on the policeman. In a close-up, we can see the black ooze coming out of her eyes. Cut to a shot from above, when the policeman's eyes turn black and he drops the handcuffs, and Maya's cheeks are suddenly clean again, with no trace of the black stuff. (00:33:45)
Continuity mistake: When Hiro gives Charlie the Japanese phrase book, Charlie flips the book over to look at the back cover, then flips it frontwards again. In the next shot, she's instantly looking at the back cover again. (00:16:20)
Continuity mistake: Episode 4.18, "The Wall" - The dried blood on Claire's neck from when she was shot toward the end of the previous episode keeps disappearing and reappearing throughout the scenes at the Carnival. (00:35:00)
Continuity mistake: At the beginning of the episode, when Tracy is talking to the waitress and freezes her mug, the position of the mug changes in her hand between consecutive shots.
Continuity mistake: When Claire is looking at the "Alice in Wonderland" dust jacket, she holds in one hand looking at the back cover, then in the next shot, she's holding it with both hands looking at the front cover. (00:24:40)
Continuity mistake: Mohinder and his friend enter Sylar's apartment. He's wearing a white shirt. In one shot, when he finds Sylar's secret room, he is wearing a dark jacket.
Suggested correction: It's not a dark jacket. It's still his shirt but since he's in the shadows, it just looks darker. You even see when the light swings you can catch a glimpse of the shirt.
