Continuity mistake: While Turk is talking to Carla the clock behind Turk changes from 1:18 to 1:25 back to 1:18 and then to 1:32 in a minutes time. (02:48:45 - 02:49:45)
Continuity mistake: When Jodie hits the deer her vehicle spins out. As it is spinning the headlights are not projecting any kind of visible beam. After the car stops, and she is facing the deer she hit, the headlight is now projecting a very bright beam to illuminate the deer on the road.
Visible crew/equipment: When Nina's just been shot, and makes it to the barn to call CTU (around 7.10am), while she's speaking on the phone there's a cameraman visible on the right hand side (DVD). (00:12:40)
Revealing mistake: When Syd's Dad rescues her in the car park, he starts shooting at the other car. After firing one shot the slide of his gun locks back (indicating it's out of bullets), but when the angle changes he carries on firing with no problems. (00:43:20)
Replacements - S1-E4
Revealing mistake: Just as the one soldier is sent flying over the wooden fence surrounding a building, you can see break away marks on the post where he will hit it. (00:34:40)