Factual error: The 1960s London policeman at the beginning is carrying a baton on his belt. British police officers didn't start carrying batons until the 1990s. Before that they only carried short truncheons in concealed pockets. (00:01:50)
Factual error: The US Air Force general is always addressed as 'Commander' Gilmour. Commander is a naval rank considerably junior to general, and the stars on his shoulders show he's a general.
Factual error: In the beginning of the movie where Austin is leading the band around the corner, the Snare Drummer is using a snare drum with a "free floating tension system" (the vertical rods on the shell). Free Floating snare systems weren't developed until the late 1980's, yet they're in 1960's London. Also, the band has a quint (5 toms) drum player. In the 60's drummers were only using 1 or 2 marching toms at a time, quints didn't become popular until the 90's.
Factual error: The rifles that the Paras are holding are SLR rifles, which were ditched by the British Army in the late 1980's for the SA-80 rifle.