Specifically, I don't think that Tony Martin is quite the poster boy for self defence he has been made out to be in some cirles. Yes, the burglars deserved to be put behind bars, but some evidence points that Mr. Martin may have not been totally in a self defense mode when he shot the burglars.
The man was victimized previously and nothing was done by the authorities to remedy the situation. He was pushed to the breaking point by a system that was forcing him into perpetual victimhood. When that happens, a man either becomes a passive sheep or he grows fangs and gets nasty.
The English government reaped what it sowed with Tony Martin. Put people into a position of helpless, repeated victimization long enough, and a certain percentage will haul off and respond in kind when they've reached their limit. Even a nice dog will bite if abused enough and given no escape.