I read there was an exchange of fire between the cops and the man in the car. Did you read something different?
I believe that is the “official version”, however:
http://www.guardian.co.uk/uk/2011/aug/07/police-attack-london-burns
What is needed in these situations is a whiff of grapeshot. We have become so squeamish as a society that we are prepared to see people killed, hundreds injured (including many police) and tens of millions in property damage, for fear that a couple of thugs may get killed. Early, decisive response is what ends this type of situation before it spirals out of control.