I totally agree that the woman in the situation should do what makes her feel safe and minimizes the drama ("don't engage the crazy") AND the impact on her, mentally and emotionally. (I'm the one who normally says, "the lessons from the NYC subways are, avoid instead of confronting.")
Remember also that I didn't suggest she "educate" him--there's no explanation, no "do you realize this is wrong?" sort of stuff. There's a simple statement--in fact, an *order*: "Leave me alone." That's not educating, and it's not necessarily engaging.
But I also think that as a culture, I think we could do with a little less "don't make scene" emphasis. And that we should include, as an option, the idea of saying, "Leave me alone" loudly enough for bystanders to hear. That THIS could be a form of protection as well, but people don't consider it an option. And bystanders don't always react appropriately; instead of stepping in to reiterate, "hey, buddy, she said to leave her alone," they give the person with the loud voice (the woman) a dirty look, or they avoid.