In some contexts, yes. However you’ll still likely have to defend charges of manslaughter. You’d have to demonstrate that the actions you took could reasonable be expected to not result in the death of the subject; and that those actions were necessary to prevent receiving grievous bodily injury or death.

To a trained person, this may be possible if they are entering a situation where they have an overview of the situation and know what they are getting into. For example, armed police stopping an unarmed thug.

However, a regular civilian, who has been woken in the middle of the night to an armed invader has no clue what to expect. And then their fight-or-flight response kicks in and they no longer have rational thought.

I think it's completely reasonable to assume that the homeowner in this case felt that his life was in immediate danger, as the attacker did enter the home with a weapon.

Lots of people defend themselves without turning their unconscious assailants into pin cushions. You seem to be fundamentally misunderstanding how reasonable force is determined. I suggest you read my other comments.

And lots more kill them. Like this guy from Milton, who was found to be not guilty after shooting a home invader to death.

If you can remove yourself from the situation the threat is over. It’s factually wrong to suggest that people can’t tell when they’ve won a fight.

It's a mistake to think that people don't misjudge the use of excessive or lethal force. Hell, even trained officers are more likely to use lethal force just for having a high heart-rate. And it takes biofeedback training in order for them to reduce (not eliminate) these errors in judgment. (link to study)

Someone broke into someone else's house in the middle of the night with a weapon (intention to hurt or kill the occupant and/or their family). As quite a few home invasions involve more than one person, how would the homeowner know that someone else isn't waiting outside, making it a 2 vs 1?

In hindsight, it's easy to say "the threat was over", but not so much when you're in that situation.

Continuing to inflict damage on an incapacitated assailant logically does nothing to prevent another potential unknown assailant from attacking you.

I totally agree, like if someone is running away from you and you shoot them in the back. I'm not aware that this is what happened in this situation.

However... you have to consider the human element: someone was attacked by someone else who intended to cause them harm. Adrenalin, and very likely "sleep inertia" could have also played a role in impairing judgment, making it difficult or even impossible to think logically in a life-or-death situation.

And the reality is, we have trained, armed officers who find it difficult to know when enough force has been applied to an unpredictable situation. I think the courts may be asking too much to think that regular citizens being put in these situations would all of a sudden think and act perfectly.