Continuity mistake: When Johnny, Roy, and Captain Stanley are rescuing the people trapped inside Olive View Hospital, they are wearing distinctively marked SCBA tanks on their backs, and when all three firemen exit the doorway, Cap is wearing an entirely different tank, and the tanks that Johnny and Roy are wearing have been switched. Then when Johnny jumps off Engine 82, his tank differs again, and when he walks over to the Battalion Chief it's changed yet again.
Continuity mistake: In Season One, Episode 10 "The Prankster": Just after Otis makes the ghost sounds from inside the house, it shows the gang standing together outside the house. Otis is with them outside, which is impossible, as he is inside the house pretending to be the ghost.
Continuity mistake: When Zeb asks Olivia about dinner he takes a whole carrot, snaps it in half, and begins chomping as he walks toward the meeting in the living room, but when Esther takes the carrot away from Zeb it's quite a whole carrot, with only the tip gone. (00:05:00)
Continuity mistake: Towards the end of the episode, Maude makes Walter breakfast and lists some things she will get done around the house. One is to paint the kitchen chairs. She spray paints the chair with Walter in it - the amount of spray paint on Walter's jacket changes thoughout the scene, especially when Maude is on the phone turning down a job.
Continuity mistake: Right before the bad guy fires his rifle through the window, Caine kicks the rifle out of his hands and the bad guy jerks backwards, away from the building. The next shot the rifleman still has the rifle in both hands, and is slammed into the building by Caine.