Take note, there was nothing said about payment in advance. He is talking about where the girl comes to your room, then after the deed is done she wants to be paid and leave, demanding the same amount agreed upon, even though she has pulled a switch from LT to ST.
The fact that you only pay the girl in the morning doesn't prevent this from happening. It just means that you haven't had it happen to you, obviously.
On my second tour(3+ yrs ago), this happened to me several times. The two times that stand out in my mind, the problem was m/l the same thing, since each time the scenario was about the same, i.e., I meet girl in bar, she is all smiles and we are getting along famously, then off to have a bit to eat and back to the room for agreed-upon LT. After a little chit chat we get down to business. In each case, I went down on the girl and she was loving it, moaning, and coming. Then I banged her. Each time, after I banged her, they showered, dressed, made excuses, and wanted to leave.
In one case, I paid in full. Just one look at that girl's face, and I knew it wasn't worth arguing with her. She had that tough look about her! With the other one, I discussed it with her at great length. Like a salesman, with each excuse she came up with, I refuted it, and tried to convince her to stay. At a certain point, it became clear to me that she would not leave without my permission. She seemed to be afraid of me. But she was desparately making up more excuses, pleading with me to let her go.
The only reason I kept trying to convince her to stay was because I really liked her, especially her a$$, which was awesome, and I had really been looking forward to cuddling up against her all night. And even though, she had a chest like a boy's, she was very, very pretty.
Finally, a bit distressed to see her go, but then what is the point of being with someone if they don't want to be there, I told her that she could go. Of course she wanted her 1000 Baht. I said NO. She protested, but I said no, that was for LT, I won't give that much. I was thinking I would give her 800, since it wasn't really the money, but the principal of keeping with the deal, that was the issue. But when she saw i wouldn't give 1000, then she said, OK, give me 500. I said fine, gave the money and she was off.
I couldn't understand at the time, until it was later that tour explained to me by another girl, what the matter was, why they were loving it one minute, then wanted to leave a little while later. Here is what the problem was:
I was banging them too long and hard. They were a bit shocked by it. I did sense it a little bit at the time, but wasn't sure about it, since they did not actually say anything to me about it. But that was just the style that I learned with American women, who mostly have the attitude of "Faster! Harder! Faster! Harder" and the longer the better. That was the kind of sex I had come to enjoy and for which I had always got a lot of appreciation from the ladies.
But those ladies were't Thai, and weren't "working girls." Consequently, I had to relearn my whole approach to sex. There are some TGs who do like the "Faster, longer, harder" approach, but I think the majority do not. Mostly they want you to come when they come, if not before.
I am sure that there are a lot of different things that could turn a girl off to a guy, some like bad breath have been mentioned. But, I think that there is usually(but not always) a reason for it, when suddenly LT turns to ST.