Character mistake: Ruth tells the Oxford professor that she read "Classics" at Oxford. That's a major mistake - Oxford doesn't offer "classics" as a course: it is called "Greats" (or "Lit Hum"), and is referred to as such by the students reading it. It might be one thing for an Oxford alumnus to call it "Classics" when speaking to someone not at Oxford, but they would never say it to a member of the Oxford faculty.
Factual error: A shipping container has a sign on it written in French, part of which reads "Attente cinq minutes...", which is intended to mean "Wait five minutes..." "Attente" is the noun "wait", not the verb, so the sign should instead read "Attendez cinq minutes..." Another sign reads "2.5m", but this should be "2,5m" as French uses a comma as a decimal point. (00:11:20)
Other mistake: Tariq has been tasked with finding hotel guests who share their surnames with American presidents. His computer screen is shown with the search in progress. The surname "Bush" appears twice (two presidents, but only one surname), and the counts for the two entries are different. In addition, the name "Truman" is misspelled as "Trueman." (00:28:15)
Audio problem: In a conversation with Colin, Zoë says "What is the point of it being able to do all this stuff if we can't see the results?" The camera then cuts away from her face, she continues "We need to find out who [name I won't embarrass myself by misspelling] is talking to." This line has been dubbed in, as it is said while the actress' face is off-screen and in a completely different tone of voice. (00:35:30)
Plot hole: Collision between the two planes would have been prevented by TCAS (traffic collision avoidance system) computer systems installed on both planes. The TCAS systems automatically coordinate with each other and issue a TA (Traffic Advisory) with an audible "TRAFFIC, TRAFFIC", then if on a course that could result in a collision or near miss, issue an RA (Resolution Advisory) to their respective flight crews. Typically one plane's flight crew is audibly ordered to "DESCEND, DESCEND" by its' TCAS and the other plane will be instructed to "CLIMB, CLIMB" by its' TCAS. The flight crew is required to follow their TCAS instructions over the air traffic controller's. All commercial airliners are required to have a functioning TCAS computer. These systems were obviously not under control of the terrorists, they were conveniently ignored in the plot. (00:03:20 - 00:06:47)