I do not pity the man who is forced to reconcile the apparent belief that the government is always right with a government official claiming that the government was wrong.
No pity required— that man doesn't exist. If people actually thought that way they'd be disabused of the notion after the first few counterexamples they encounter.
Just-world, like other stereotyping biases is so insidious because the mistaken belief starts with the truth: "The government is usually right, so it's (very likely) right in this case (and the rightness justifies the outcome)". You can, perhaps, debate the "usually" but that misses the point: In terms of _justice_ and human rights it is improper and immoral to reason using coarse prior probabilities: You should be no more likely to convict a black person because statistically black people commit more crimes, people should be judged on their own merits. The underlying fallacy in many instance of just-world is the mistaken belief the its proper to apply your belief that the world is generally just to a specific case of potential injustice.
So there is no dissonance for most— they think "well, I always believed the government was only usually right. No one is perfect, and see— the system worked!".
See also: http://en.wikipedia.org/wiki/Just-world_hypothesis