The difference is that Stevens could afford good lawyers. He could buy the time and the patience, and the research and the experts, and the continued investigation after his actual conviction. Thousands of people currently languishing in prison can't afford any of that and, I assure you, a shocking number of them are there because prosecutors barbered the Bill of Rights, either because they simply didn't care, or because of the pressure from their elected bosses -- and, therefore, from the public at large -- to put bad people away and the devil take the hindmost. Our criminal justice system is shredding its reputation for being fair because it is so hellbent on maintaining its reputation for being sincere.
How do I know? Because, the same day that the special investigator was roasting the Stevens prosecutors on a spit, the Department of Justice paid a guy named Nino Lyons $140,000 because the federal prosecutors in his case relied on witnesses so blatantly corrupt that they shouldn't have been trusted to wind their own watches. The difference? Nino Lyons did three years in jail. Why?
Because we wanted him to, that's why.