From these reports, this man died defending himself.
I think Australia's gun laws are a travesty and I think SWAMPSNIPER is on the money when a few posts after yours, he refers to 'effective self defense' because a gun in the right hands makes it a lot easier to defend against a gun in the wrong hands - but, please, don't make the mistake of assuming being unarmed, means a person doesn't have the right to defend themselves. Mr Johnson did have that right under Australian law, under common law. He may not have had the means, but he had the right.
And as there are people who would like even that right taken away, I think the distinction is important.
Are you conversant with gun laws in NZ? A friend there says he may own a gun, but cannot use it in self-defense. That sounds crazy.
Without the means the right is nothing but empty rhetoric.
How can you have the right if they refuse you access to the means???