Other mistake: At about 5:36 Jack and Ramon are playing Russian Roulette. Right before Ramon nods to Jack indicating the bullet will be fired, we see a shot of the gun from behind revealing the next chamber to be empty. The trigger would need to be pulled two more times in order to fire the bullet.
Other mistake: In the shootout at the stadium, several times when Jack fires a gun the sound of the gun firing is heard but it is obvious that the gun did NOT fire. Most noticeable when Jack fires the third shot at the man behind the wall and when he is struggling for the gun with the last guy who he beats up.
Other mistake: In the car Jack practises his cover story posing as a German arms dealer. But when he mentions his fake name Ernst Meier he says it in the English way, not in the German one. No man with German language knowledge would say it in this very wrong way, and it would give him away immediately.
Other mistake: Mason asks Nina the ETA on the tactical teams, to which she responds "Five on the Alpha, Eight on the Beta." There's a timecheck 3 minutes later, and after the break they still haven't arrived. Team Alpha continues to be more and more late than estimated. Jack begins to break into a van, still no tactical team has arrived. Jack kills Victor Drazen at the 17:47 time check, still no back up. They finally show up at around the 31 minute mark.
Other mistake: During the explosion from the tape recorder, there is a very short explosion shot recycled from a previous season (when Christopher locks Jack in a bunker and tries to kill him with a bomb placed in a clipboard). This old footage is also seen when that tape recorder explosion is shown on recaps of the event in season 6.