How about if the police officers that tried to stop the attack BEFORE it happened had had a gun? Maybe they would not have fled and called in reinforcements?
I would tend to agree though, even with a gun, you still have to have an indication of the attack, and have time to react, as well as the mindset to be able to defend yourself, but who was saved by the laws outlawing guns in these two situations?
Obviously all the gun control laws of both France and Australia didn't stop these mentally unstable individuals getting their hands on guns. So why should we disarm all the people who haven't hurt someone because some have? How will removing more guns used for legitimate purposes slow down or stop attacks by people who are already willing to break the law? How did it work out to have guns outlawed in France and Australia when these people were still able to get a hold of these weapons?