I agree, the guides you can read on /r/seduction [1] are so hilarious that I can't believe anybody who writes these would be dumb enough to actually try them.
Sounds more like the guy just managed to get over his ex and "get back out there".
How much of that was due to the fact the girl liked him already (Women don't generally invite single guys over on their own unless they have at least some interest in them, or are already good friends) and how much was due to his "swagger", "DHV", "negs" and "kino" is up in the air.
That is one of the biggest misperceptions in the mainstream: that PUA is about using negs/DHV/kino. the reality is that most good methods will emphasize that a decent part of this is a numbers game and simply about talking to enough girls. That in itself is a skill.
As an example, my results shot up significantly when I went from talk to 1 girl every 4 hours at the beginning to 5-10 an hour. I happen to try and find a girl who naturally digs me than one who needs convincing.
Everybody's going to get lucky some of the time, especially when PUA methods encourage hitting up as many women as you can see.
What I find amazing is when some of the more hardcore PUAs declare that hookups without the sleazy tactics "don't count", as part of the cultish nature of the community.
Edit: fwr, yes, the real benefits come from a bit of confidence, and it is often enough to overcome the ridiculous tactics.
Oh sure, my wing is a hardcore nerd who's been with over 250 girls. He actually has an Excel for past 5 years charting his "lays" per month. Note that this is not typical and I would personally never go to the extreme that he is at.
For me, I know if I talk to 8 random girls on the street on average I will score one date. It is normal for me to get 2-3 dates over the course of a weekend.
As I said, these kinds of thank-you's are common. I just linked to the first one I found. You can conclude that either 1) people who read seddit are a bunch of idiots and don't learn anything from it or 2) it works for some of them. I'm inclined to believe #2.
A lof of PUA stuff is oversold, but there is plenty of good advice to be found as well. It definitely made a difference for me.
[1] http://www.reddit.com/r/seduction -> sidebar guides