Continuity mistake: When Kim is working undercover, dressed up in Saunder's daughter's clothes, she comes out of the Ladies' toilets wearing brown trainers. As she sits down at the library computer, you see she is wearing her very high heeled shoes. A few seconds later, as she is walking between the library shelves, she is wearing brown trainers.
Continuity mistake: During the hostage exchange, there is a shot of the black man waiting for Jane Saunders to walk to him, in the background we can just see a man stood behind a car door. However, in the wider shots and when Saunders jumps out of his car, the man is not there.
Continuity mistake: When Tony locks down Tech One from his office, the CCTV screen he's watching shows the monitors in there displaying the "locked down" message moments before they actually change to the message in the next shot within Tech One.
Continuity mistake: In the teachers' lounge Jack tells Chase that the second floor is cleared. When he doesn't get an answer he realises something is wrong and runs down to the floor Chase is searching. After he's cut Chase's hand off he runs out into the hallway and into the lounge which is suddenly on the same floor Chase was on.
Continuity mistake: When Michelle shoots the escaping hotel customer, her gun shows a jammed shell casing while she points her gun at him. The jammed casing wasn't there after she fired her final warning shots and disapears suddenly just before she shoots him down.
Continuity mistake: In the scene where Wayne and Fox are in Sherry's house searching for the pill container, right before Sherry asks, "What's going on here?" Wayne is seen wearing latex gloves. The camera then cuts to Sherry. When it cuts back to Wayne, his gloves have magically disappeared.