The idea of using reasonable force in a home invasion makes sense. E.g. when an armed intruder breaks into my house, threatens me, my wife and my young daughter, and in response I shoot him in the face, pretty sure most juries would acquit on the grounds that my family's lives were in danger. On the other hand, if it was some punk unarmed kid trying to steal some random shit, I probably shouldn't have carte blanche in deciding whether the kid lives or dies.
Sidenote for our friends south of the border: it's much less likely that the intruder has a gun than it would be in the US. In the case he does have a gun, I believe you are justified in responding accordingly with your own firearm, even if it leads to the intruder's death. You break into someone's property threatening with a gun, all bets are off. But I'm pretty sure most sane juries would agree with that anyway.