The answer from the article you posted:
On Sunday night, after being taken back to the holiday island of Samui, the two men were manhandled by police past onlookers into the investigation centre in handcuffs, their heads bowed.
Think she'd have been any safer on a stretch of the Gulf Coast? And, had you read the story, you'd know her "whiteness" had nothing to do with it.
The crew of the trawler, in Lamai Bay, were allegedly drinking heavily and watching pornographic DVDs when one of the pair announced: "I want to rape someone".
I don't think the story really indicates much one way or another. But the perps did seek their victim on a beach where, at that time, any woman they found would more likely be "farang" than Thai. I expect they knew this.