Continuity mistake: There is a scene early in the film where the garage explodes. A view from high up shows the explosion. Later in the film when Jim and Frank are on the rooftop, you get practically the same view but look at the area where the explosion was earlier. Everything is perfectly normal and there is NO sign of any explosion.
Factual error: In the scene on the motorway where we see Manchester burning, the road signs are for the A421 and A507, which are at M1 junction 13 near Milton Keynes and nowhere near Manchester.
Continuity mistake: In the final scene where Jim, Selena, and Hannah are waving down the jet flying overhead, Selena is wearing a green sweater/coat over two layers of red shirts. It cuts away and returns to her suddenly lacking the green sweater. She was seen jumping and waving already with it on, so it's not like it fell off from movement.
Continuity mistake: In the scene where Major Henry West pulls a deceased Private Davis out of their army truck, we see three infected running towards the truck, however Major Henry West shoots two of them and the other infected just disappears.
Factual error: The film states that the 42nd blockade is located on the M602 motorway, 27 miles outside of Manchester. The M602 is 3.4 miles away from Manchester at its farthest point and is barely three miles in total. It is a very short motorway. It only has 3 junctions. The filming location was actually the M1, outside Milton Keynes.
Revealing mistake: When Jim is walking across the Westminster bridge and shouts "Hello?" for the first time, in the next shot you can see a blob on the bridge (right of picture). This is all that's left of a car going across the bridge, that wasn't painted out completely.
Plot hole: When someone is in a coma for 28 days, the hospital would have AT LEAST have catheterized said person, however when Jim wakes up in the hospital he is not attached to anything but an IV.
Suggested correction: What happened when Jim was admitted is never revealed. Being that there is nothing to show what happened when he was admitted its impossible to say certain procedures would have been followed or more simply the hospital might have not undertaken them. More importantly we don't know when the virus hit certain areas. In addition Jim was taken in around the time the virus was first starting to spread and hospitals would be the most likely place someone infected would be taken to so many working or staying there would have been the first to have been infected. With that scenario the staff at the hospital might have neglected some of their patients because of how quickly the virus spread.
If the hospitals would have been some of the first infection sites, why would Jim have survived the entire 28 days? I doubt someone was refilling his IV on a regular schedule if the patients are becoming violent animals, which would suggest he would have died of dehydration before starvation would have gotten to him. Also, why would those infected ignore Jim while he was comatose? Would it not be 'sporting'? Given how instinctual they seem to become I don't see how comatose would be any different from intoxicated or deeply asleep. Did all of those sorts avoid infection as well?
Answering the question in order... 1. It isn't known how long Jim has been in hospital. It may have only been a few days. 2. Maybe they didn't know he was there, or alive. It isn't shown how the infected react to an unconscious person. Perhaps they ignore them. 3. The infected have no concept of 'sporting'. 4. Possibly. They just don't feature in this story.
Factual error: In the scenes driving to Manchester the motorway is completely clear of traffic, no abandoned vehicles of any sort. With an outbreak like this happening the motorway would be gridlocked.
