The details I have on this are incomplete, but it got coverage in Hong Kong. The American in question was an English teacher who may have gotten mixed up in one of the increasing number of English school semi-scams in China.
There is a growing number of reports of people having problems after answering ads to be English teachers at independent language schools. When they arrive, they find that the terms they agreed to are not being honored - longer hours, more classes, lower pay, passports withheld, promised plane tickets not delivered, etc, etc.
This poor guy had phoned his father a few hours before he died, reportedly saying he'd "never been so scared in his life".
Speculation is that he was threatened, then murdered, by people associated with the dodgy school who didn't like his intentions to quit or report them to the authorities or whatever.
As for the girls, caveat emptor. Keep your wits about you and you should be fine. Like anywhere in Asia - Keep an eye on your drink, ask for drink prices as you go, pay as you go if possible, don't go into karaoke places that SWs invite you to, get into taxis that YOU arrange/hail, go to YOUR room not hers, pay after you play, arrange price before, and, if you don't speak the language and are really paranoid, forbid mobile phone calls after she's in your room.
And wrap that rascal!