I think that's probably situational. There could be aspects in which they couldn't apologize. If the person really is in a bad mood, it's unlikely that they'll turn around a few minutes later, suddenly feeling better and then being apologetic. And it could also be the case that the person was just a random person who could never contact you again to apologize.

I really like the article overall. It seems somewhat like common sense, and even reading it, I know the next time I bump into a situation like this, it'd still be difficult for me to see it this way.