Hanno wrote: I am sure that if you have the right cash and the right motivation there is no need to doctor a stolen passport, you get a "real" fake one.
To make a "real" fake passport, you use bits from other passports, which have been stolen or sold by junkies as a last ditch effort to make money. Forgers will do a variety of things with the stolen passports, including removing and exchanging the inside pages, for example. Sometimes they may just resell a passport of someone with similar physical descriptors, but if that passport was reported as lost or stolen than its value has reduced dramatically, as it can be checked against a database. These 42 passports, presumably mostly from Western countries, would have incredible worth to forgers.
I don't see why it's hard to fathom that there would be any level of organized crime in Sihanoukville, or Cambodia at all for that matter. It could have even been orchestrated by criminals in Thailand, that when they heard that tourists in Sihanoukville send they passports en masse to Phnom Penh in buses they realized it would be the easiest and most lucrative snatch job ever.