Should Gaddafi have been killed?

Christopher Hitchens argues that he should have been put on trial instead:

There can be no doubt that the proven elimination of the old symbols of torture and fear has an emancipating effect, at least in the short term. But I would say that this effect is subject to rapidly diminishing returns, which became evident in Iraq when Moqtada al-Sadr’s unpolished acolytes got the job of conducting the execution of Saddam Hussein. There are sectarian scars still remaining from that botched and sordid episode, and I shall be very surprised if similar resentments were not created among many Libyans on Thursday. Too late to repair that now. But it will be a shame if the killing of the Qaddafis continues and an insult if the summons to the Hague continues to be ignored.