My brother in law spent a couple years at a "camp" in Vietnam so I am familiar with the way they railroad suspects and then treat them brutally in the prison system of Vietnam. He was actually a police officer and was imprisoned for a mistake (seeking petty bribes) that was committed not by him but by his subordinate. The prosecutors publicly acknowledged after the arrest that the offender was the subordinate, but held my brother in law responsible anyway. I mean, hey, he was already under arrest. They couldn't just say "oops" and let him go. Nope. They had to save face by keeping him in prison for a couple years. He's free now, but he is a physical and emotional wreck. And he prbably got favorable treatment from the guards. Five years as a political prisoner (considered lower than all other living things in prison, including the cockroaches) for Pham might as well be life. The guards in those places are the type of country bumpkins who grew up kicking cats, slaughtering pigs and have now graduated to sadism's big leagues. They would love to shit on an intellectual like Pham.
Get the book "Vietnamese Gulag". You'll see how brutal and arbitrary the VN justice system is.