David Aaronovitch was more noted for rhetoric than reasoning when he was a Leftist National Union of Students "hack" in my university days. He was a smug "lefter than thou," faux-prole, sent-down-from Oxbridge, scruff then. He is a screw-loose political columnist now. Plus ca change.
Why stop at blaming the 7/7 and 24/7 London terrorists for Jean Charles de Menezes death? Certainly the Metropolitan Police would not have been running around our capital city like panic-stricken incompetents that day, had it not been for those terrorists. But the terrorists would not have been homicidal maniacs were it not for their warped ideology. And their warped ideology could not have been propagated were it not for the mullahs in their mosques. And the mosques would never have existed were it not for Islam. By his reasoning (not mine) an equally-correct answer to his stupid question is "The Prophet Mohammed (pbuh)"
One of the joys of worshipping at the altar of the Bitch Goddess of Socialism, is that everything is someone else's fault. Or often no-one else's (aka "Society's"). Aaronovitch has been an acolyte for so long that he has lost all ability to think in terms of personal responsibility (except on the part of political opponents).
As he has posed this interesting question however, let me answer it seriously. Who really killed Jean Charles de Menezes? Here is my (possibly incomplete) list:
1. Tony Blair who, as Prime Minister, authorised a policy to order the police to kill people in circumstances where the officers might have no lawful defence to a charge of murder;
2. The Home Secretary who instructed the Metropolitan Police Commissioner to implement that policy;
3. The Metropolitan Police Commissioner who accepted that instruction;
4. The officers who so failed to exercise their personal judgement on the scene that they killed an innocent man under police restraint although he was so clad that he could not concealed a bomb.
We can only speculate as to the state of mind of the killers as they pulled their triggers. The officer restraining Jean Charles has given evidence that he feared for his own life. I think it's fair to infer that their blood was up. Their commander (with the charming loyalty of the State apparatchik) has given evidence that she ordered them not to kill him. They did it anyway.
Please let's face the facts here. An innocent man was summarily executed in our name in the most brutal way - his head blown off with illegal dum dum bullets - by a squad of our public servants. This was done on the orders of our Government and without the sanction of Parliament. Our "servants" then told us a barrage of lies about the dead man to distract attention from what they had done. These people, God help us, work for us. In a sense, we are all guilty until we rise up against them.