If I may, Ms. Pond, I think there is a slight difference between the example that you provide. That is, under normal circumstances under a domestic dispute, there will be an assault...by two people in a residence, to which you know who the perpetrator is, and you can arrest for that assault because it's an offence to which you can prove whom the person is that did the assault. Given the example of a police officer being called to a scene to which there is a person in distress, they enter the building or a place, they see a person, male or female, who has obviously been assaulted—let's use the case of a black eye or something that can visibly be seen as a black eye, or a physical assault—and there is another person there who is telling the police, “Get lost. This is none of your business. It has nothing to do with you.”
Then you ask the victim, him or her, “Can you tell me what happened?” Under the circumstance that they will say, “There there is nothing wrong, so please leave”. What authority would the police have to speak with that person if it were not for section 213, in relation to an offence under section 213?