At the end of the last episode Jack was interrogating Joe Prado in the van at CTU parking lot. The episode ended when Jack knocked Prado unconscious. When this episode starts Prado is suddenly being treated by CTU's medical team.
When we Jack is sneaking through the hallways in the back of the club, the clock reveals that it is 01:25:12. A couple minutes later, when Marwan is preparing to film a terrorist message on tape, the clock reveals that it is 01:23:02. (This error is not present in the Season 4 DVD set, meaning it is likely that the error was present in broadcast but corrected for the DVD. The corrected version shows the time when Jack is in the hallways as 1:21:12)
Ex-president David Palmer's right hand can clearly be seen each time he is on the telephone without any scarring. At the end of the 24 hours (6 - 7 a.m.), the scarring is visible again.
This episode starts at an impossible point. It is not possible that Prado was taken by CTU Medical Staff from the car, brought to a bed, revived, then began treatment in just 3 seconds. It is also not possible for Jack to have gone into CTU, told Bill what happened, have Bill assemble a team with Curtis and start prepping that team with Jack, in a matter of 3-4 minutes.
At 8:34 the crew that stole the warhead unpacked it from a case clearly marked US Army. Only USAF and USN would have access to warheads. In this case more likely USAF.
After Jack confirmed on video that Marwan was inside the club, he should've immediately called Curtis and the tact teams to enter the building, instead two whole seconds.