Continuity mistake: After the first scene you can see Elizabeth and her student standing together talking in the background. Then it shows him calling out to her as she's going to go down the stairs. (00:00:49)
Just Another Normal Day - S1-E4
Continuity mistake: In the morning kitchen scene with the kids eating breakfast, the daughter bends down and grabs a blue box of cereal from the bottom cupboard. Next cut from the opposite angle, shows that she now has a yellow box of cereal instead. (00:12:25)
Sea Change - S3-E1
Continuity mistake: Henry takes off his watch while sitting bedside. He stands up to take off his suit jacket, goes into the closet and returns into the bedroom, and his watch is back on his wrist. (00:14:00 - 00:15:00)
Continuity mistake: When Secretary McCord is dressing in her closet while speaking on the phone, she tucks in her blouse, which is then untucked a moment later.
Gift Horse - S3-E11
Continuity mistake: Stephanie McCord picks up Mr. Hobbs at Washington National Airport. When she greets him they are outside the terminal, a lady in dark clothes with a white scarf pulling a suitcase walks by as they stop and talk. After Stephanie puts Mr. Hobbs' suitcase in the trunk, the same lady is seen walking past again in the same direction. (00:01:00)
Convergence - S3-E17
Continuity mistake: In the sit room, when the president is trying to decide whether to intercept the smugglers' aircraft, the local time displayed On the Clock in the background jumps from 19:12 to 19:58, back to 19:12, then to 20:13, then to 19:08. It then jumps to 19:53, then 19:59, then back to 19:15, then to 19:02. It then jumps to 20:00, before going back to 19:15 and finally finishing 19:02. All in the space of about 2 minutes of ‘real time'. (00:01:10 - 00:02:45)
Night Watch - S4-E22
Continuity mistake: You see the same scene twice in this episode, where NSA Ellen Hill gets a phonecall from stratcom, in the second scene (which is a rerun of the "first" scene), her ringtone is completely different. (00:04:40 - 00:10:50)