One of the most understated sides of this story is main characters negation to the fact the "infected" actually had human feelings. We were supposed to draw our own conclusions from reaction of Alpha Dog to kidnapping of his missus, and then from Fred trap, but somehow it all got muddy and badly shown in the movie. Many people I spoke to thought Fred trap was not set by the infected, but Neville himself. Probably because the video rental scene, with Fred, was shown much earlier, only once, and everyone forgot about it. Showing it once more would definitely help - you know, just to underline that this was Neville's daily routine, that the video rental shop "crowd" were the only "people" he spoke to every day, so seeing Fred suddenly on the street was supposed to make you feel eeiry.
But then the story drops completely. We don't get to understand the infected were actually vampires, clever and thinking in their own way. It's almost as if the screenplay writter left and was replaced by someone who completely misunderstood the plot...
If the cure was his blood, then letting the infected byte him would turn them into humans. Well, thought Neville. In that case, why don't I just blow myself up. Wtf writes these things...