You still don't quite get it. It wasn't the car that was being approached head on that got in the collision. That car was in a situation to see the whole thing coming and just put the brakes on.

It was driver who out of the blue realized that there was a car less than 6 inches away, going at least 20 mph faster, who needs to be where they are now or else they'll be in a headfirst collision. That driver's attention is focused on escaping from that threat, leading to a panicked swerve into the next car over.

No, I had it right. I've actually been in that situation -- a car trying to pass me across a double line into oncoming traffic -- and IIRC my reaction was to brake hard. Not necessarily a better reaction.

Ah, the "car approaching head-on" is the perspective of the immigrant.

Yup. That's the scenario exactly. And yes, braking hard is a better reaction. It makes life easier for the passer. The passing car probably came from behind you, and so there is likely a space. If there isn't, the car behind can see the whole scenario unfolding and has the opportunity to react. So all over it is much safer than swerving.

The only case it won't help is if the passing car is swerving, gets hit, and spins out. But in that case there is probably nothing you could do to avoid an accident.

There's not necessarily a car approaching head on at all. It's about someone passing more aggressively than expected (keeping much closer to the passed car than is normal in western countries, for example) causing the passed car to freak out and swerve away, into another car. All the cars involved are going in the same direction.