I'm with Dipesh Parmar in an earlier review. This fairly long film was never dull, but it did not satisfy either. Anna Paquin plays Lisa, an intelligent teenage girl with the erratic judgement of her years, feeling passionately about many things but expressing herself often in a way which angers or upsets those around her - and herself, in the end. She's prickly and self-righteous, vulnerable and aggressive. I don't want to give away essential elements of the plot, but her behaviour with the sympathetic maths teacher (Matt Damon), for example, is an instance of how she can be both manipulative and needy, with consequences for both of them which could be very serious. Anyway, as the result of a piece of very silly behaviour on her part and criminal carelessness on the part of the driver (Mark Ruffalo), she is partly responsible for a terrible accident in which a woman is killed by a 'bus which goes through a red light. She is with the woman as she dies - a terrible event very convincingly depicted - and her hysterical outbursts at that point are surely forgiveable. However, that is how she often is later in the film in quite different circumstances. She creates confrontation in the classroom, at home, with friends. After lying to the police, she decides to alter her witness account so that the driver, whom at that point she seems to blame totally, may be properly punished, and she goes after him relentlessly. That is really the main plot element, and it works itself out as the film goes on.
Lisa is not an unconvincing character ; she's just not likeable. At times she is the victim of circumstances. More often she creates trouble and aggravates it. She distresses a decent boy who likes her. She frequently upsets her mother, who is herself vulnerable. She is unable to deal successfully with her absent father, with whom she would like to spend time but to whom she talks on the 'phone, usually without very much connection, and whose offer of time spent together in the end is withdrawn. There are times when you would just like to slap her which is what (metaphorically) the dead woman's friend Emily eventually does, recognising that, while Lisa has been caught up in an event which would be traumatic for anyone, she is nonetheless making a narrative of it to suit herself, sometimes at the expense of others. I should say here that Anna Paquin's characteristic expression of startled self-righteousness turning to aggression is completely convincing ; she is very good, as are all the cast. J. Smith-Cameron as her mother also deserves special mention for a very good, understatedly fragile performance.
How much of this is the result of the film's editing, from 3 hours down to 2 and a quarter? It may be that links are missing, that some scenes, played out more fully, might carry more weight, but there is no way of knowing. There are moments when there are curious leaps, and one (in the maths teacher's apartment) when there was clear bad editing. In the end, the film seems to me to portray accurately some aspects of adolescent behaviour, but to be unsatisfactory as a dramatic whole.
P.S. (31st. July 2012) Another Amazon user has made me aware that this DVD is the full 3-hour version - I was writing about a version seen in the cinema, and should have made that clear. Thanks to my informant!