I posted this on the Comments section over at EuroPundits. I thought it was kind of clever and didn't want it to die in the Comments where nobody would read it, so here it is.
Here's a bad analogy. There are five of us in the same ninth grade class who are getting pushed around by Billy the bully. He keeps extorting our lunch money and the like. So we get together and two of us, Johnny Bull and Sammy Yank, propose that we all get together, jump Billy, take him down, and whale on him for a while. Then he'll leave us all alone. Johnny and Sammy calculate that Billy isn't nearly as tough as he lets on, anyway, and they volunteer to lead the charge while the other guys back them up. Now, there are risks; Billy might pop one of us good while we're taking him down. Johnny and Sammy figure this risk is worth it, but little Jacques, little Gerhard, and little Guy are so scared of being the one dude who gets popped by Billy that they chicken out of helping Johnny and Sammy jump Billy, finding various excuses for doing so.
Well, Johnny and Sammy do jump Billy and they win; Billy doesn't even get the chance to pop either of them just because they're so fired up and pissed off and ready to kick Billy's ass good. Gerhard, Jacques, and Guy have now gained the benefits of Johnny and Sammy's ass-kicking on Billy: ie, Billy isn't going to be pushing anyone around anymore, not even them--but they haven't taken the risk of Billy's smacking them one. They therefore feel ashamed; that is, somebody else did something courageous which they chickened out of doing themselves. They don't like to feel ashamed; therefore, they will say that Sammy and Johnny aren't really so tough, that they cheated when they jumped Billy, that they beat up Billy too badly after they got him down, that they just did it because they want to take over Billy's extortion racket, and even that Billy wasn't such a bad guy after all and that Sammy and Johnny were the real bad guys because, after all, they were the ones who started the violence when they jumped Billy.
That's what they call self-justification, a way of relieving the cognitive dissonance caused by Gerhard's, Guy's and Jacques's desire to maintain their good opinions of themselves and their certain knowledge, which they are unwilling to admit consciously, that they didn't have the guts to face Billy.