* BrokenBase: See ContestedSequel.
* ContestedSequel: While the film was generally well-received, there's a significant portion of fans who feel it paled in comparison to its predecessor.
* IdiotPlot: The whole situation goes completely down the toilet due to the main characters making the dumbest and most counterproductive decisions.
* InferredHolocaust: [[spoiler:It's heavily implied the infection has reached the European mainland]] by the end.
** [[spoiler: And assuming Andy's the one who spread it there ([[UnwittingInstigatorOfDoom and he probably is]]), he and Tammy are likely dead.]]
* TheScrappy: Andy and Tammy by virtue of being [[UnwittingInstigatorOfDoom Unwitting Instigators of Doom]], and not by bad luck or being at the wrong place at the wrong time, but by their own stupid choices. Not only were they largely responsible for the new outbreak of Rage Virus in Britain, but to make matters worse, [[spoiler: their selfishness and downright stupid actions causes the rest of the world to get infected, too]]. And yet through all of this, they still are [[spoiler: [[EverybodyDies the only ones who make it out alive]]]]. Ask pretty much any group of people who have seen the movie, and you'll find at least one person who was angry that [[BrokenAesop the kids didn't die for their bad behavior]].
** Looking at the [[InferredHolocaust last shot]] in the movie, for all we know, they ''did''.
** The American military, consistently portrayed as unnecessarily authoritarian and violent, end up [[spoiler:killing civilians by the truckload]] to contain the virus. Brutal? Of course. But if it had been completed, the continent (and possibly the rest of the world save for outlying islands and the American continents) would have been spared the rage infection. Instead, it's the compassionate turncoat who dooms humanity by giving the kids, [[TooDumbToLive WHO BROKE THE QUARANTINE FOR FUN]] and [[spoiler:became unaffected carriers of the virus]], a lift across the English Channel to safety. It's next to impossible not to root for the gun-wielding maniacs while this is going on.
*** Nobody knew [[spoiler:Andy had become a carrier]], since everyone who knew [[spoiler:Alice had been one]] was dead (though the fact that Andy's eye looked like the eye of someone infected should have tipped the pilot off that something was wrong with him). And the military definitely held the IdiotBall in a few places - herding all the civilians into one parking garage that obviously wasn't secure [[spoiler:given how easily Infected!Don broke in]] is almost a case of TooDumbToLive.
*** It depends on whether you believe the ends justify the means, particularly in a situation that's going to be FUBAR whatever you do to remedy it, but the U.S. military firing into the crowd makes it hard to root for the 'gun-wielding maniacs'. [[AlternateCharacterInterpretation Unless, of course, the soldiers are firing]] at the civilians because [[MercyKill they know they'll probably be infected]].
**** We saw at least one sniper MercyKill a fellow soldier that was getting swarmed by the infected.
** Incinerating the infected area (and, KillEmAll) is, in fact, the '''only''' sane method for dealing with a highly infectious ''quickly lethal'' disease spreading through a population. Once a virus (or other biological weapon-like disease) breaks out of quarantine into any substantial population, there's simply no other way to contain it. Physical geographic barriers (such as Britain being an island) can limit the possible spread, but, inside those limits, it's simply impossible to stop via normal selective targeting. '''All''' militaries use the methods described in the movie when dealing with that sort of situation, and it's not only the only effective strategy, it's also the only ''moral'' one - sacrifice some to protect many. Of course, given the IdiotBall the US military had been holding up until then, it shouldn't have gotten to that point, but, once it did, ordering the soldiers to kill everyone (including uninfected) is the Right Thing.
** Don's daughter berates him for [[spoiler:not being sure his wife was dead]]. She completely ignores the fact that if he would have gone back to help his wife, the kids would have been out two parents instead of just one.
*** Don did technically lie when he said he'd seen Alice die. He can't really be blamed as he was too preoccupied with getting the hell away to confirm her death.
* TheWoobie: Alice cannot catch a break in this movie. Her husband abandons her when an Infected separates them, and he just books it instead of trying to save her. She is immune, however, and flees back to her house in London where she stays in hiding for months. She is eventually found by the military, who bring her back to District 1 and plan on killing her to run tests on her corpse to find a cure. Beforehand, however, Don visits her to beg for her forgiveness for fleeing, then kisses her...[[spoiler: which causes him to become Infected and kill her in the most drawn out and painful death in the movie, all while she is strapped to a table. Then her body is lit on fire from the firebombing]]. Good lord.
** Don for some. He blames himself for [[spoiler: abandoning his wife to the Infected and then having to lie to his children about that. Add to the fact that he reunited with Alice, only to get infected, kill her, and chase down his children]]. Ouch.
* ThisIsYourPremiseOnDrugs: According to Creator/JeremyRenner, a.k.a. Sgt Doyle, "It's everything I think [[Film/TwentyEightDaysLater the first one]] is, but on crack."
* WhatAnIdiot: Sure, Don, kiss your infected wife, never mind she's an unaffected carrier of a virus that turns you into a raging murderous monster more or less instantaneously. Also, kudos to the military for leaving her room unguarded.
** Sure, kids, break out of the safe area and sneak out into a deserted, ransacked Britain just 'cause. It's not like a quarantine is important or anything, and it's not like they ''told you exactly why they needed a quarantine.''
** Sure, US Army, go through the trouble of building and elaborate containment area for potentially infected survivors, and put in a confirmed carrier of the virus and proceed ''not to post any guards around her'', as well as granting regular civilians unrestricted access to said containment areas! What could possibly go wrong?