When Lisa was acting deranged at the stadium...
When Lisa was acting deranged at the stadium was that a foreshadowing of her entering the tertiary stage of infection later in the movie or did the writers actually not realize that, as written, the character was crazy?
I would like to think it was deliberate, but militating against that is the fact that the writers did not show the character of Neville having a normal reaction to Lisa's insane behavior.
If I was in a post-apocalyptic situation, where most of the survivors was suffering from insanity caused by a bio-war agent, and I ran into a female survivor who with no provocation assaulted me repeatedly, including
when I was driving a motorcycle WITH HER ON IT, I would conclude the bitch was crazy, and since she had
access to firearms, I would get as far away from her as humanly possible, as soon as possible.