You ain't on the jury. Why does the dad have to present YOU with evidence? You seem to be condemning him without all the facts.
OK, so I don't have them either, but if a reasonably intelligent man, cognizant of the law, feels he's justified, I'd tend to agree with him a lot more than you.
We'd have a lot less of these slime if people took care of it themselves.
I unfortunately have stood in this man's shoes so I do feel I have a pretty good idea of how he was feeling, and I still think he was wrong to do what he did...