Idiot Ball: The world has been all but destroyed with a tiny population of still living humans remaining, yet Umbrella is still pissing about with bio-organic weaponry, hosting board meetings and generally acting as if they still had somebody to sell their products to. It's not until the last film that it's revealed all of this was planned.
Rescued from the Scrappy Heap: L.J. drops his Modern Minstrelsy shtick from the last movie and becomes an actual character rather than a "street flava" joke-dispensing device. Unfortunately, it's only then that he gets killed off.
The Scrappy: This film solidifed Alice's status as such in the franchise due to how her God-Mode Sue status was taken Up to 11. At the end of the film, she has not only essentially made all the characters from the games play second fiddle to her, in no small part due to having psychic powers completely alien to the games, but has also gained an army of clones with her same psychic powers.
They Wasted a Perfectly Good Character: Given that there is a teenage girl in the convoy who gets a lot of screentime, the viewer could be forgiven for guessing she's Angela Ashford after the Time Skip and then getting surprised when she's revealed to be a new character named K-Mart. Had she been really Angie, it would have opened the door to many interesting storylines due to her lingering T-Virus mutation and family-like relationship with Carlos and Alice (and even although her actress Sophie Vavasseur wasn't available, the mentioned Time Skip would have allowed to recast her believably). Instead, the character of Angela is literally forgotten in the film, and unlike Jill she never reappears or is mentioned again in the franchise.
They Wasted a Perfectly Good Plot: Alternately to what is proposed above, Angie's absence from the film is explained in the novelization as having been murdered by Alice under Umbrella's cybernetic mind control. Despite being a plot point that should have produced a lot of drama and could have been used to give Alice more depth, nothing of this is used in the film, where Alice and Carlos are positively cheerful in their reunion and never dedicate a word to their vanished friend.