He would have had better luck hiding in the US, IMO. A white guy in a largely non-white country sticks out like a sore thumb, especially a fugitive. Rescinding use of his various online accounts, utilizing cash and public transportation as well as altering his appearance and working on his accent, he would've easily blended into the masses here. LE has a hard enough time tracking down some serious domestic offenders as it is.
As mentioned in the article, he was living in an apartment above an expat bar, on the very touristy riverside strip in Phnom Penh. It sounds like he wasn't really trying to hide. Perhaps because he was chronically ill, and needed to make frequent hospital visits anyway?
I think it's pretty unlikely, even if he did take various measures to hide, that he'd be able to if influential foreign governments were putting pressure on the Cambodian government to find him. Cambodia is a pretty tiny country.
