They surely make mistakes, occasionally letting dangerous people back out on the streets, but it's their job to test the convict in long conversations and tests. That's the law. They have a closer look at him again, they decide. After all we've heard about the man, I wouldn't be surprised if Breivik pretended to be harmless to do stuff all over again, even in his mid 50s. But who knows? Maybe, and more likely, he'll still talk proudly about his deed and hopefully never see the light of day again.