It really depends on how the guy said "I like that skirt!" She said he was yelling it, and if he said it with an intentionally suggestive tone, then I can understand being annoyed. I wouldn't respond the same way she did, probably just ignore him.
On the other hand, we've both found that a lot of people who are seeing persecution and discrimination where there is none tend to change their story when retelling it, sometimes (as with the woman who claimed to have spit in the face of a cashier for supposedly trying to touch her inappropriately by handing her change back) to the point of absurdity. Either they're intentionally spicing it up to make it sound more justified or they're thinking back on it afterward and letting their own opinions color the memory of the events.
For all we know, it was a regular guy who was genuinely complimenting her on her skirt and suddenly being shouted at for it.
I don't think his intentions were entirely pure by the way he called her a bitch at the end. I think if he did just intend it as a passing compliment, he would've apologized when she told him to back the fuck off and left it at that. A personal anecdote. About this time last year I was walking through the mall and a guy I've never seen told me "hey, I like your boots." I wasn't too confident in my voice so I walked by him without saying anything. After a few steps I hear him say "fine then, be a bitch." So, clearly, he was just using that innocent little compliment because he was hoping I would melt before his eyes and sleep with him right there. How can a woman tell the difference between someone who sincerely means those words and someone using those sweet nothings solely because they degrade women to sex objects? We can't. But a good way to not look like a tool is if a woman wants to be left alone, then apologize, and leave her alone. No man, except Chris Hemsworth, is entitled to our time.
Likewise, street harassment isn't just "hey there sugartits" or "nice ass." It's any form of talking to someone when they don't want it. Women hear both of them on a regular basis, that is "hey, I like your boots" and "nice ass." Clearly, the latter is just gonna get an annoyed sigh from me. The former, depending on the time of day, how I feel, whether or not I feel you're sincere, etc. can result in me being quiet, me asking to be left alone, or me opening up to you. If you get brushed off and push the issue, it's harassment.
And Chit, this is one of those things you don't understand. I say that from being in your shoes. Pre-transition, I thought "so what, a couple of guys want to talk to women, what's the big deal?" It wasn't until I started passing that society just becomes a torrent of guys who can't leave you alone. Like ever. Like walking through town, through the mall, riding the bus, on the metro, waiting in line somewhere, driving, walking to class, filling your car with gas, having coffee with friends, reading a book, sitting in the sun, playing pokemon of all things, I could go on.
True or not, because of this, I love it when women stand up to creepy men. I can't do anything in public without some creepy guy hitting on me (usually about 3 people in two hours*) and I've always kept quiet or polite. I wish I could tell people off like her, real or fake, I've seen countless creepy people who deserve that treatment. And the thing is, the creepy people just love to rationalize their actions from annoying & harassing to "well, it's only a compliment." Because of how common this rationalization is and how much men just don't understand it, in claims of street harassment, it would be more than safe to defer to the person being harassed. Who, sadly, is almost always a woman**.
*I made a game out of it one day while walking through the mall doing Christmas shopping. I called it "count the creepers." That number has been surprisingly consistent over the last 7 months (not including when I go clubbing).
**Not that men don't face street harassment here and there, just never at the same frequency as near always to understand how annoying it is.
