Day 4: 3:00 P.M.-4:00 P.M. - S4-E9
Continuity mistake: In the previous episode, when Jack and Tony try to stop the helicopter, they drive off the road and hit the front bumper and lose their front license plate. This is also visible in this episode as Jack and Tony wait for backup and when they drive off there is still no license plate, but about 8 minutes later, when they arrive, the license plate is back on. Since the show is in real time and they arrived in the exact time they said they would, they couldn't have stopped to get it fixed or anything.
Day 4: 6:00 P.M.-7:00 P.M. - S4-E12
Continuity mistake: When Driscoll leaves CTU, Secretary Heller asks Tony to call Division to request a replacement. Moments later, Heller says he still wants to call District. (00:14:00 - 00:14:40)
Day 4: 9:00 P.M.-10:00 P.M. - S4-E15
Continuity mistake: Chloe tells Michelle that she's confirmed Marwan's identity using voice tags from McLennan Forrester, but all of the computer records at MF were wiped out a few episodes earlier by the EMP, according to both the MF employees and CTU. The fact that they didn't get any information from the company except for the printouts Jack and Paul extracted was a major plot point a few hours ago, so even if a real EMP wouldn't do this, the fact that it's stated repeatedly in the show means it should hold true within the series; Chloe suddenly having information from them an hour or so later is discontinuous, and thus a mistake.
Day 4: 10:00 P.M.-11:00 P.M. - S4-E16
Continuity mistake: When Jack shoots Nicole through the wall, she slides down, smearing blood on the wall. However when Jack comes to check if she is dead, no blood is seen on the wall.
Day 4: 11:00 P.M.-12:00 A.M. - S4-E17
Continuity mistake: When Jason and his wife are trying to escape from Marwan, they run through a corridor filled with water puddles. A few seconds later, one of Marwan's men goes through the same corridor to follow them, but none of the puddles had any ripples, which they should have considering the amount of water and time elapsed.
Day 4: 11:00 P.M.-12:00 A.M. - S4-E17
Continuity mistake: When Jack gets out of the helicopter near the reserve power station, he slams the helicopter door, but it immediately bounces back open. In the next shot its closed.
Day 4: 12:00 A.M.-1:00 A.M. - S4-E18
Continuity mistake: To get crucial information from Prado, Jack offers his resignation to Buchanan, and takes Prado on as a private citizen. But Jack doesn't work for CTU; he works for DOD, and is at CTU on a provisional basis.
Day 4: 1:00 A.M.-2:00 A.M. - S4-E19
Continuity mistake: At the very end of Episode 18, Jack knocks out Joe Prado after breaking his thumb and getting information from him. At the very beginning of Episode 19, we see Prado already being treated for his injuries, with a hand splint, and nurses checking his head, within the CTU clinic. Even if you factor in the opening recap sequence at the beginning of every episode, that means that Joe Prado regained consciousness, Jack unhooked his handcuffs, and dragged him back to CTU in three minutes or less.
Day 4: 5:00 A.M.-6:00 A.M. - S4-E23
Continuity mistake: In the first scene where we see Tony as a hostage, Mandy comes over to him and he has a white gag in his mouth, which is taut. Mandy says, "Is she gonna do the same for you?" and the camera cuts back to Tony, whose gag is now limp on both sides.
Day 5: 7:00 A.M.-8:00 A.M. - S5-E1
Continuity mistake: Season 5 Episode 1 Hour 07:00 A.M. The bad guy goes for Chloe and starts running at full speed close to the door (15 steps?) at 00:17:24. After 9 seconds "running," he barely is at the door. (00:17:25)
Day 5: 9:00 A.M.-10:00 A.M. - S5-E3
Continuity mistake: During Episode 3 of Season 5, the terrorists take Derek in front of live television. When the terrorists force him on his knees, you can see a splatter of blood on the floor from the body of the last victim that was shot there. As time is running out, another shot of Derek being held by the terrorists is shown, and the mere splatter of blood that had been near his knees is now a noticeably big pool of blood. Nobody has harmed Derek yet, and there are no signs that he is bleeding. So where did all that blood come from?
Day 5: 11:00 A.M.-12:00 P.M. - S5-E5
Continuity mistake: Season five, 5th hour. Lynn knows about the four people who knew Jack was still alive, he mentions their names and talks to Jack about it. Yet when they are told Tony wants to speak with Jack, Lynn looks completely puzzled and Jack tells him that he knew Tony. Minutes earlier Lynn already knew that.
Day 5: 1:00 PM - 2:00 PM - S5-E7
Continuity mistake: In the "Previously on." montage, Ivan Erwich tells Walt Cummings "Your country is about to pay a very steep price for betraying us." But at the end of the previous episode, Erwich never says "for betraying us."
Day 5: 1:00 PM - 2:00 PM - S5-E7
Continuity mistake: When Spenser tells Jack that someone else is in Rossler's penthouse, he says "In the bedroom to your right," but Jack then glances to his left.
Day 5: 5:00 PM - 6:00 PM - S5-E11
Continuity mistake: When Agent Aaron Pierce steps out of the helicopter, the right half of his face is severely wounded, with lots of blood and a bandage on it. 12 minutes later, when he is back in the Presidential house, he's talking with Miss. Logan and his face is completely clean, with not a single scratch or sign of wounds on his right half of the face. (00:12:55 - 00:25:00)
Day 5: 9:00 PM - 10:00 PM - S5-E15
Continuity mistake: Season 5 - 9pm-10pm, at 9:41pm. - Technical weapon error. When Jack takes the Federal Marshal's' Glock pistol, in an effort to add drama, he holds the pistol in his right hand and cocks it with his left hand by grabbing the slide, pulling it back, and releasing it to chamber another round. However, after he does this, the camera zooms in on the gun as it is pointed at Colette's' head and you can see that the slide is still back on the gun and NOT capable of firing at all.
Day 6: 8:00 AM - 9:00 AM - S6-E3
Continuity mistake: When Jack slams his carjacked SUV into the terrorist's car, only its driver's side door acquires damage, but when it cuts to a close-up the car also has substantial damage over the front tire.
Day 6: 12:00 PM - 1:00 PM - S6-E7
Continuity mistake: At the very end of the previous episode (approx 11:59 AM), Jack and Phillip are chained at the back of the van, and in the closeup Jack's handcuff double bar faces up on his right wrist. This moment is shown in the recap at the start of this episode. When the van reaches the dump site (approx 12:07 PM), Jack and Phillip are unchained and now Jack's handcuff single bar faces up on his right wrist. (00:01:55 - 00:07:55)
Day 6: 2:00 PM - 3:00 PM - S6-E9
Continuity mistake: When Milo begins to drive the tactical van with Marilyn, the driver's side door acquires significant damage, but when being shot at a moment later, the door is undamaged.
Day 6: 6:00 PM - 7:00 PM - S6-E13
Continuity mistake: When Logan walks into Martha's bungalow, there is a deliberate close-up of the photograph with Martha and Anya, in a narrow goldtone frame. Oddly, in following shots, that photo is in a wide width, white frame. Additionally, the arrangement of all the frames on that table changes quite a bit as well.
Chosen answer: Nobody knew, not even the writers, until at least halfway through the season when they were writing the end. They wanted to keep all options open.
Nick N.