Is Major Henry West really a Manipulative Bastard, or is he a good man driven insane by the situation surrounding him?
The rest of the soldiers too. Are they really driven mad and gone monstrous enough to rape innocent women? How many of them would have actually gone through with it? Some theorise that they may have raped Selena but would have stopped short of raping Hannah too. Notably one of the soldiers is seen shaking his head sadly as they leave Hannah and Selena to change.
Anonymous Benefactor: Right at the start of the main story, once Jim wakes up, someone, maybe a doctor or a nurse, locked his hospital room door and shoved the key under the door, so that he could get out if he woke from his coma, this probably inspired the more famous hospital opening from The Walking Dead which debuted only a year later.
Awesome Music: "In the House, In a Heartbeat," a steadily increasing anxiety attack of a song that perfectly matches the climax.
The film also uses "East Hastings" by Godspeed You! Black Emperor to haunting effect in the beginning, as Jim wanders the deserted streets of London.
Go up to a group of fans of this movie and ask one simple question - 'is 28 Days Later a zombie movie?' Then stand back and watch the ensuing punch-up.
The third act revolving around the soldiers. Some fans hate the fact that the film takes a break from the infected to focus on Jim trying to stop Hannah and Selena from being raped - while others feel that it's a great direction to take the story in. A large amount of Danny Boyle's films - The Beach, Slumdog Millionaire, Sunshine feature a seemingly insignificant plot element coming into the forefront to be the main conflict of the third act - so fans can't agree on whether it works or not.
Cue Irony: The scene where Jim and Selena celebrate with Frank and Hannah? It was shot on the day of the September 11th terrorist attacks. Danny Boyle lampshaded how strange it felt for them to shoot an uplifting scene on such a day.
Ending Fatigue: For "surviving the apocalypse" movie fans, this movie starts off great but then makes a hard left midway through, sticking the main characters with the soldiers who take the forefront as antagonists and carries a different tone to match.
Fridge Logic: The main reason why the "Radical Alternate Ending", which wouldve involved a blood transfusion as a way to cure the rage virus, wasnt used in favor of what was shown in the final film.
Danny Boyle: "And that was the problem right there with this ending. We established that one drop in the eye can infect someone, then how in the flying fuck are we gonna sell that the idea that this blood transfusion idea was gonna work? What do you do, clean out every capillary and vein with bleach?"
Selena's cold and cynical attitude is explained in a backstory that Naomie Harris and Danny Boyle came up with together: she had to kill her whole family in one afternoon, including an infected little brother. Knowing this makes her reaction to Frank's death even harder to take, as she's suddenly going through it all over again.
The start of the third act's conflict revealing that the soldiers are planning to rape Selena and Hannah out of desperation. Jim is horrified that desperation would drive them to do such a thing. Then once he's nearly been executed, he himself has to resort to brutal murder to stop the soldiers - showing that he's Not So Different.
Heartwarming in Hindsight: There is something heartwarming about three then-unknown actors playing people trying to survive in an After the End scenario - now with the hindsight that all three are now established in the film business.
Ho Yay: Mixed with some Foe Yay in that Henry seems really fond of Jim, constantly touching him, and while he promises women for his soldiers, he himself doesn't seem that interested in them beyond some vague rambling about "The Future".
Moral Event Horizon: Major Henry West reveals that he put the announcement on the blockade solely to attract female survivors - and that he's going to allow his men to do whatever they want with Selena and Hannah. This of course solidifies him as the new antagonist.
Brendan Gleeson (the father who joins the first two midway through the film) is a well-respected character actor whose first major role was in Braveheart and went on to play Alastor 'Mad-Eye' Moody in the Harry Potter films and Ken Daley in In Bruges. Gleeson, an Irishman, also played Winston Churchill in the HBO TV movie Into The Storm.
Christopher Eccleston (who was also featured in Danny Boyle's film Shallow Grave) went on to play the Ninth Doctor and is known as this for British audiences/Who fans. Americans would know him as Destro in the GI Joe live-action film, Claude from Heroes, and Matt Jamison in The Leftovers.
Ron the Death Eater: Some fans blame the activists and only them for the virus getting out. While they do share a lot of blame, they're not the ones who created the virus. And as stated below, the scientist doesn't exactly do the best job of explaining why they shouldn't be let out. At that point, the activists only know that animals are imprisoned to be tested on, almost certainly for a way to weaponize the virus.
Undercut slightly by the fact that the only things the two stories have in common are that they are set After the End and start with the protagonist waking up alone in a hospital and emerging into an abandoned London.
The researcher who couldn't come up with a more convincing explanation for why the animals shouldn't be let out of the cages other than "Rage". "Oh hey, they're carrying a highly infectious and dangerous disease we're studying for god knows what horrible reason" might have been just a wee bit more convincing.
Jim wanders off from the group into a restaurant when they stop to get gas. Selena reminds him they have enough food, he sarcastically says he's looking for cheeseburgers - but he ends up getting attacked and having to kill an infected child.