Revealing mistake: When Bakari is fighting Banning with the machete, the blade gets stuck in some metal bars. In this shot you can see a break line visible in the blade where it snaps a few seconds later. (01:17:00)
Revealing mistake: When Mike is throwing Bakari around and starts his speech, pay close attention to Bakari's shirt. The padding is visible underneath it in some shots. (01:17:30)
Factual error: The role of MI6 shown in the film actually falls under the purview of MI5, Britain's domestic intelligence service; as the country's version of the CIA, MI6's mandate is the covert collection of foreign intelligence overseas.
Other mistake: Colin Salmon in Box Command introduces himself to Banning as Chief Inspector. However, the rank on his shirt is of a Commander rank.
Factual error: When the president arrives at the church, he gets out of the limousine, and they close the door. The Secret Service keeps it open for emergencies. The church door also gets closed, same issue. An agent would be there keeping it open. Then the entire motorcade is missing including the second limousine which is always present.
Plot hole: Banning knows where there is an MI6 safe house but has "no option" but to head for the US Embassy. He could have gone for the Tower of London, Buckingham Palace, Knightsbridge Barracks, Downing Street, the Palace of Westminster or Scotland yard, all knee deep in security.
Suggested correction: The whole premise of not being able to go to the embassy is because they (the terrorists) will expect it. Banning also makes it clear to Asher that the entire security services are no longer to be trusted due to an insider. Going to any place "knee deep in security" is literally walking into a potential terrorist. The head of the UK response team even states they don't know who can be trusted and they need to eliminate the ones that have infiltrated the police forces. Hence the MI6 safe house.
Suggested correction: Considering the fact that there was a mole inside Scotland Yard, going there wasn't really an option.
Factual error: The rescue team at the MI6 safehouse takes ages to arrive. A spec-ops team with helicopters should have been on alert and arrived in minutes.
Factual error: Marine One should have rushed directly to a warship on the water. The navy would have had many of them on alert well before, and Marine One would have had a pre-planned escape route secured by fighter jets.
Factual error: In such an insecure situation, the SS would have arranged a secure bunker ahead of time for VIPs on site. There is no mention of it.
Factual error: During the attack on the President at the church, where is the rest of the motorcade? The second limousine, several SS armored SUVs and the entire Counter Assault Team are missing.
Deliberate mistake: Where are the motorcades for the other world leaders?
Plot hole: They find the terrorists by the electricity they're using, but they're using generators, off the grid.
