When Urban Prelac's handcuffs were temporarily removed in Ljubljana's courtroom, he seized the opportunity and escaped. On his way out he managed to lock the doors, trapping the astonished pair of guards and everyone else in the room. The key was apparently on the outside of the door. As of yet there is no trace of him.
Rather how incompetent other people can be. One of our ex-olympics got arrested for dealing with cannabis, As he was just about to be sentenced, he had no handcuffs on him during the court, neither during the small break in the middle of it. Instead of getting back to the courtroom after the break ended, he simply walked out of the building and took a plane somewhere distant. Nobody stopped him. He finally got caught years later hiding somewhere in South-America.