Well, obviously, he wasn't. Because he didn't know, didn't remember:
#1 Rule of Outcall: You don't pay her for sex. You pay her to LEAVE.

Perhaps menu change. Perhaps LT became ST. So he offers her half. But he doesn't consider her perspective. Because that's a MAJOR loss of face for her, returning to her friends with "how much?" That quiet, subservient, smiling girl (just because she's smiling doesn't mean she's happy), suddenly is not so quiet, not so subservient, not smiling, now SCREAMING. He doesn't want his neighbors disturbed... Maybe she "mentions" she's only 17... He wants to shut her up, but a small face/big hands or 17 year old neck/strong hands... not a good match.

All over WHAT? 500 baht? Approximately $20au. Know how to read the room. Know when to hold, know when to fold.

An ABSOLUTE TRAGEDY for the girl and her family, especially the muckraking. For him... SCUM, hopefully a long term in general population.