Right after the virus breaks out again and the medical officer grabs the two kids from isolation she is trying to get them out of the building when a soldier stops them. The soldier keeps calling her "sir" when in fact female officers in the US armed forces are addressed as "ma'am" by those of lesser rank, not "sir".
While trying to escape with the survivors, Scarlett is shot on the inside-front of her left leg, which she bandages up. Later in the abandoned fairground/park she re-bandages her wound and it has moved to the outside-front of the leg.
Flynn's helicopter changes multiple times. He falls asleep in an Aerospatiale Gazelle. When he attempts to rescue Doyle, he is flying an Aerospatiale A-Star. When he lands in the stadium to rescue Doyle and the children, he is once again flying an Aerospatiale Gazelle.
When the girl is in the pizza shop, a window above the Greek restaurant is alternately open and shut in different shots.
When Scarlet shoots the guard infected by Don, blood splatters over the window, covering the area where his hands are. In the close up to his hands, most of the blood is gone, except for a few drips.
When Scarlett is looking at the kids through the night-vision scope on the rifle in the subway, there's no magnification on them at all, their entire faces and upper bodies are visible. A rifle scope would be so zoomed into something close that it would be barely recognizable.
When Andy is jumping on the trampoline, the grass is trimmed. After 6 months of neglect, the grass would be overgrown, and the trampoline covered in debris.
At 1:18:11 and later Doyle and survivors chasing by waves of nerve gas cover their nose and mouth with hands and/or clothing. Also they are in a car covered by cloud of gas and think it will help. It's useless/senseless behavior. In fact nerve gas acts immediately through skin pores, eyes, ears in milliseconds causing loss of control of the respiratory muscles, convulsions, involuntary urination and defecation, and death by asphyxiation. Fact is they would be dead in a blink of the eye with all open orifices. Any clothing can prevent inhaling gas. Also gas can be/is often invisible, not a big white cloud.
After repeated attempts to start the car using the starter, Doyle decides to push-start the car to help Andy, Scarlet and Tammy escape the gas. Push-starting only works when the battery doesn't have enough power to activate the starter. Since the starter was working, push-starting would be useless.
When Andy & Tam escape to re-visit their old home, they are shown crossing Tower Bridge, which as they have started their journey from the Isle of Dogs, means they are travelling South across the river, but the next shot shows them passing the 'London Gherkin', which is built on the former site of the Baltic Exchange, St Mary Axe, in the City of London, on the North Bank.
About halfway into the movie, the "infected" charge frantically down the dark tunnel. When they reach the stairs, they all slow down, take small steps, and grab the side rails to avoid falling.
Just after the helicopter lifts off from Wembley Stadium, in the shot following the white-out transition, traffic can be seen moving in the roads in the bottom-right of the shot.
When the children are riding the motorbike through the cemetery, fresh flowers are on one of the graves. Since the cemetery is outside the quarantine zone, there should be no-one around to visit the deceased.
When Don is running across the field from the farmhouse to the boat jetty, you can see fresh tire marks in the grass from earlier takes.
On Doyle's M4 he has an EOTech and a PVS-14 NVG night vision scope. Whenever it shows him looking down the sight he has the standard cross hair, when in fact the EOTech would be a red ring with a dot in the middle.
The film takes place in or around 2002, at that time the Wembley Stadium was in an early state of construction and would not have looked like it did.
At Charing Cross station, during Don and Scarlet's showdown, a Jubilee Line train is on the platform. The Jubilee Line hasn't stopped at Charing Cross since 1999.
(at around 56 mins) Doyle fires his gun three times to kill four infected men. However, at the third shot, two of them fall, but since they weren't lined, it would be impossible to kill both men with only one shot.
Many times, the actual sounds of the Aerospatiale Gazelle are replaced by a more familiar helicopter sound, although in a few places, you do hear the Gazelle's distinctive high rotor speed and squealing from the Fenestron tail rotor.
(at 32:15) When the two children are riding the motorbike on Tower Bridge, just as you see Andy's face, there is a cameraman standing on the pavement.
During the firebombing, a burning infected is attacking a human. A cameraman and a crew member are visible as the camera turns away.
When Flynn is hovering next to Doyle, you can clearly see the stunt pilot, wearing a black balaclava, glasses, and a radio headset.
When the aircraft with repatriated people approaches London, it is headed to Runway 09 at London City Airport. When the passengers get off the aircraft, they are at Stansted Airport, in the terminal buildings.
The route the survivors took around London, and the distances involved, would not be possible in the time frame as shown in the film.
Flynn's helicopter is a British Gazelle. The US force could have taken control of it after arriving, but considering the state of the country, and the fact that the US uses their own equipment when possible, it's not likely.
The DLR train carrying the settlers from the airport has "Greenwich" on the front. Greenwich is across the river from Isle of Dogs, so it wouldn't have been quarantined.
The group escaping from Canary Wharf cover the distance between the southern perimeter of Canary Wharf and the entrance to the Greenwich Foot Tunnel in a little under two minutes (based on dialogue.) This is approximately one mile in a straight line and would be impossible to accomplish on foot in the time frame.
There is no security of Alice's quarantined room. No guards, not even a single security camera. Don is not scrutinized when he enters her room. The Americans did not even know there was a danger until bodies were found when the now-infected Don escapes. The entire outbreak hinges on this major oversight.
It would've been highly improbable for Don to have unrestricted access to Alice's cell. Considering the virus was extremely contagious and the fact that Don was still merely a civilian, he would've never gained clearance to a place as potentially dangerous as Alice's cell, because of such risk of infection. Only certain people such as Major Scarlett or General Stone would've had clearance to enter Alice's room.
Andy and Tammy should not have been able to sneak out of the safe zone so easily given how well-protected it was supposed to be.
During the escape from Canary Wharf, Flynn tells Doyle he will extract them from open ground at Regent's Park. Doyle and his group then travel south through the Greenwich Foot Tunnel. The southern exit from this is a short walk from Greenwich Park. No reason is given for Doyle not picking them up from this open ground, even though it would be just as easy and also much safer.
In the surgery scenes, people are only wearing surgical masks. The virus is transferred via blood and body fluids, so everyone in quarantine should have worn goggles, especially the doctor.
General Stone says that the Infection does not "cross species." However, the original outbreak began when humans came in contact with infected chimps. This is most likely caused by a confusion between Order and Species. The Rage virus can infect all species within the primate order, but it cannot infect any other order (aquatic life forms for example).
Scarlett wears her hair in a ponytail while in uniform. The US Army requires females in uniform to wear their hair above their collar.