I read the article. And I'm not terribly fond of the hot air this guy is blowing. He stops just short of accusing the guy across the street of being a coward for calling the police rather than trying a 100 yard shot with his pistol (at a guy with an AK-47), or closing the gap to get a better shot. I don't care if he is supposed to be one of the "best instructors in the country," I call "SHEEP DOG" on this article.
Here's my position. (Copied and pasted from another thread.)
I cannot emphasize enough. It boils down to situational awareness.
In most states, the standard for defending oneself is the "reasonable person" standard: If you reasonably believe you are in danger and defend yourself, your actions are covered under the law in most states. (Even if there was a misunderstanding of the alleged assailant's intent.)
However - when intervening on behalf of another, in most states the "reasonable person" standard does not apply, and your actions are weighed against the facts in evidence.
For example - you come across one person holding another at gunpoint. You draw and order him to put down his weapon...then when he refuses and the situation seems to escalate, you fire and the shot is lethal. If it turns out that the armed person was the assailant (a robber for example), then you're covered. If it turns out that the armed person was a homeowner, and the person being held at gunpoint was a would-be burglar who had been chased out of the home - then you ARE GUILTY of manslaughter at very least because your actions are weighed against facts...not against the "reasonable person" standard. (If you don't believe me - ask an attorney. I'm not going to engage in debate on this example.)
This is why it is CRITICAL to know what you're getting into. Is that woman screaming in the alley a victim? Or a prostitute? Or a robber? Or a drug addict/dealer? Is that guy a thug beating up on her? Or an undercover cop trying to make an arrest? Or a robbery victim trying to get away?
Extreme examples? Unlikely scenarios? Maybe, maybe not. But that's why I'm emphasizing that you have to BE AWARE of what you're getting into, and what the risks are, before you decide to intervene on behalf of a stranger.