Living in a large city, hearing drunken people screaming at each other in the street is not an extremely uncommon occurence for me. Here’s (generally speaking, I don’t use a check list) what I do.
1)Watch what’s happening (which isn’t very convenient since my appartment isn’t facing the street, so I have to climb on something to open a tiny rear window in the back of the appartment). In most, it doesn’t seem to be anything serious or worth bothering.
2)If I’m unsure about what’s happening or think it could escalate, I make my watching obvious (opening the window, switching the light on, showing up, etc…), assuming that someone watching might deter people from going violent.
Beside this point, if I still feel concerned that something foul could happen, it depends on the circumstances. Usually I go out and watch from a distance (I take a phone and my knife, just in case), and wait until the people involved have wandered away or apparently have calmed down.
A couple of time, I shouted from my window (I live in the 7th story of a building), asking if something was amiss or if someone was in trouble. Once people calmed down and left, another time I was answered yes, shouted that I was calling the police and did so. A couple of time, I called the police and just told them that I was concerned and described exactly what I was witnessing. On occasions I told the people to calm down.
Only once I was directly involved in the issue, and it turned very weird, since I ended up being chased down the street by the victim (yes…the victim…), who was brandishing a butcher’s knife (no kidding). On all other instances, things turned out not to be something serious, people calmed down or, generally, wandered away.
However, I must say that
1°) contrarily to the poster, I don’t have any family to protect from anything. I’ve no clue how one feels when one does.
2°) There never was any serious or obvious violence involved (except in the “butcher knife” instance…and even then I didn’t know what was happening exactly). The only instances when I saw someone being actually beat by other strangers was in the subway, which is a very different situation, with many people around, etc…). If I knew I was about to face an obviously very violent guy like in the OP example, and alone in my appartment, I don’t know for sure, but I suppose I wouldn’t try to risk my limbs, and I would just call the police.
Anyway, I make a point of always erring on the safe side when in doubt and assume there might be something serious happening and act accordingly. Not specifically in these kind of situations, but for instance, I’ve been known to call the emergency services when I thought that something might be wrong with someone, asking people how they feel or checking on motionless homeless people to make sure they were just sleeping, stopping on the road when noticing something worrying (and once, it ended in another very weird situation I’m still wondering about).
So, I likely wouldn’t risk my neck to help a stranger in a dangerous situation, but I always try to do something which might be useful, and perhaps more importantly, always err on the side of caution, thinking it’s best to assume the worst and be proved wrong rather that ignore a situation which would turn to be actually very serious. Perhaps it’s related to my upbringing in a little village rather than in an anonymous town, but I feel we’ve a duty to keep an eye on other people, and like some other posters, I would like people, on the overall, to be more reactive in these kind of situation. Being reactive doesn’t necessarily imply taking any serious risk for oneself.
As for the OP behavior, I couldn’t give an opinion for the reasons I already mentionned (no family to care for, and never witnessed such a violent behavior from home). Except for one thing. I believe he should have called the police as soon as the guy began hitting the woman. He wouldn’t have taken any risk nor for him, nor for his family by doing so. So, I don’t really feel concerned with him being a coward or not (I’m personnally more on the coward side, anyway), but I think he shouldn’t have just watched while someone was being beaten up in front of his house. I know he did call the police eventually, but he shouldn’t have waited until things turned that ugly.
However, I know from experience (both as a witness and as a victim of assault) that these kind of events are rather confusing, that’s it’s difficult to figure out what exactly is happening, difficult to make’s one’s mind, and difficult to react in an adapted way quickly (and that the sitution often turns to be very different from what it looked like). So, I won’t cast too many stones to him. But I hope it will be food for thought for him, and that if he ever happen to be in a similar situation (the issue being that the situation will never be exactly similar), he will have a clearer idea of what he should or shouldn’t do. Also, I would note on the positive side that he actually feel concerned about his behavior and is wondering about it. A lot of people would just shrug it off, and wouldn’t care.
More generally, I believe people should, on occasion, think about what they would/should/could do when faced with such unusual situations. It’s essentially impossible to think and react promptly on the spot, so having thought about it beforehand might help you to react in a (more) appropriate way (be it hiding in your basement, taking pictures and selling them to the local papers, loading your shotgun, heroically engaging the bad guy to protect the kid, calling the police, that’s irrelevant to this point) . With the caveat that what will actually happen will be totally different from what you expected, and that you likely won’t react in the way you expected, either.