Wow, all the time? Such a globetrotter. I live and work there most of the year.
But if you're insinuating that it's "that" kind of stuff he's after he'll be fine in any case and getting a damn bodyguard is ridiculous beyond reason. Even the seedy parts of Bangkok or Pattaya are safe enough that you can go there alone. He won't actually be alone either becuase there is litteraly millions of turists passing through there every year.
Unless he's actually doing drugs or something that the police is targeting then he'll be just fine. Spent a week in Copenhagen just a few weeks back en I litteraly saw more brawls and drunk people getting into trouble then I did in the the last 8 month in Bangkok and Korat.