The English system isn't based on liberal policies, its based on state authoritarianism. The article points out that carrying any kind of weapon for self defence is illegal. The current gun controls were brought in by the Major (Conservative) government, thus they have nothing to do with Socialism.
If gun laws were liberalised, I doubt that it would have a positive effect on the crime statistics since there is no tradition of gun ownership for self defence in Britain. In fact, it would probably make it even easier for criminals to get firearms. Also this article fails to compare the murder rate in America with that in Britain, could it be that this fact would damage the article's argument?
Obviously, the law on self defence needs changing so that the victim or someone who helps the victim are not in danger of prosecution. Unfortunately, the British people are not citizens, they have no rights to enforce laws, they are subjects of the state which believes that only it has the right to enforce the law.