The president is shown riding in a Mercedes-Benz limousine. In fact, the presidential limousine (referred to as "The Beast" by the Secret Service) accompanies the president and is used by him when he travels. In the unlikely event that the British government would provide transportation for the president, the vehicle used would be a British-made Rolls Royce or Bentley from the government or royal fleet, and certainly not a German-made Mercedes-Benz.
When Kate is being escorted out of the CTU building and calls Jordan on the guard's cell phone, the phone display reads 3:34 despite the show taking place between 11:06 a.m. and 12:00 p.m.
When Kate pulls out her phone to call about Jack escaping, it is clear that her phone is still on the home screen and not a phone call.
When Mark Boudreau reads Jack's personnel file, Jack's brother Graem's name is misspelled "Graeme".
It was established that Jack Bauer was hiding somewhere in East London. However, the map shown of his whereabouts is actually at Chambers Wharf, Bermondsey, which is on the south side of the River Thames (the area known as East London is north of the river).