I think there is a difference between "having sympathy" for someone who gets their legs broken or their throat slashed or their body otherwise seriously damaged when, frankly, they shouldn't have been breaking the law in the first place, and preferring that people don't go too far. I have no sympathy for the burglars -- and think that the not guilty verdict in this case is quite right -- but I wouldn't celebrate their deaths either, if it had gone that far.
Besides which, someone who is capable of killing another human being after losing their temper in what could be, in the cold light of day, comparatively trivial circumstances, is capable of doing the same when there was no justification at all. I don't see that smashing someone's brains out is at all appropriate when they're trying to nick a TV/ radio/ computer -- and anyone who does think that it's perfectly appropriate is, I think, just as much a danger to society as the burglars are.