Haven't seen the latest, but when the story broke some claimed he wasn't a burglar...mind you 3 or 4 lads out at 3pm in someone else's house, if they were breaking in and attacked the guy, maybe he can claim self defence. It's a very grey area of the law isn't it. If he is coming at you it's ok to use reasonable force but if he's trying to get away you have to let them, apparently.
EDIT:
We had an attempted break in a while back, I have weights at home and chased them with a dumbell bar,about 18inches and solid steel, they ran off so I returned to secure the house, but I'm sure if I caught them in my house I'd have used it. You can't take the chance they won't turn and come at you with something far worse. If I had of come at them from the side/behind I'd have gone for the knees or arm to disable them, not the head though.