The accused may be protecting someone who had knowledge after the fact, or had possession of items belonging to Samantha. Nobody directly involved in the murder itself, but "accessories after the fact" or some other crime of that nature. Also, we don't know what the police know and don't know, so it's hard to speculate.
I just find it hard ascribing positive qualities to him, like protectiveness, when there is no demonstrable basis for that. Right now, he is accused of a crime that requires the qualities of a committed woman bashing




, and a very strong element of cowardice thrown in. I would bet good dollars he would not have tried out his killing skills on a bloke. He chose a woman, a generation older than he.
It's difficult to see how the accused, who has without doubt, all the advantages that Australia can bestow on a person, Young, Tall, Male , White, Privately Educated, Tradesman, Supportive Parents, who are still married, and living in their own home, Girlfriend, Friends, Sporting Prowess, Steady Employment, and not just sporting but FOOTBALL, the Victorian Religion, has any call on any citizen to find sympathetic qualities in this killer.