There was a similar case in Finland, except that the guy was holding a "gun." Later it turned out that it was a airsoft gun that had looked real (we don't have to paint the barrels yellow or anything) and when he had pointed the gun at police they shot him in the leg.
Well, that police officer did have a MP5 rather than a pistol so he could shoot accurately but still, this guy had a knife so they could have at least tried to use a taser or OC spray or something.