Seems he wasn't much of an agent-lower level bureaucrat basically-how did he have the will to stand up to the brainwashing and come out to win the day?
"It's the system, Lara. People will be different after the Revolution."
[deleted]
When he gets transferred to Dalby, Dalby reads out the file on him, mentioning things like "insubordinate", "trickster" and finishing with "possible criminal tendencies". Dalby says they may have a use for that last quality. Basically, the straight arrow, conventional type is not necessarily in demand, or at least needs to be balanced by someone like Palmer who acts and thinks outside the box and is somewhat amoral. Neither Dalby nor Ross trust him - for example, Ross has Jean spying on him - but they think someone like him is useful.
The brainwashing was the least convincing part, but Chinese/Eastern Bloc agencies were credited with almost supernatural brainwashing powers after the Korean War, and this finds its way into films of the 1950s and 1960s.
"Chicken soup - with a *beep* straw."