In Kanada müssen die Haushalte „angemessene Gewalt“ gegen einen Eindringling anwenden. Das ist vollkommen vernünftig

Its important to note, that reasonable is relative to the specific circumstances of that encounter.  it is not an arbitrary standard, it doesn’t require „perfect awareness“, or anything of that sort. Nor does it require „exact proportionality“; if they don’t have a weapon, I can’t use one. It doesn’t require you to know the intent of the victim nor does it care. It is concerned with your intent and your actions only. These are the claims of people who clearly have never read what S 34 or the case law says

The law simply stated is: with the facts of a given situation, were your actions not excessive or unreasonable?

It is not an excuse. It is not a bar to being charged.  Police or the Crown are not required to consider self-defence prior to charging you. Self-defence is an affirmative defence for trial, which means the accused needs to claim it and prove that their actions fall within its scope. 

That proof is generally minimal: I saw them armed. I thought they were moving towards the bedroom. I’d met them before and knew them to be violent.  Enough to establish you had *reason* to act in a certain way.

The counter-argument is that it must be shown to be *unreasonable*.  Witness testimony that they didn’t attack or move towards you, but you charged them.  Wounds that show they were fleeing at the time.  Lack of any weapon while you had a shotgun.  Prior history of conflict. Evidence to your intent being not defence but offence.

Sending a person to prison because they struggled with and eventually killed someone after being woken up in the middle of the night by that person *stabbing them in the head* is in fact unreasonable. Everyone who disagrees is literally insane.